Unwrap removal (#1842)

This removes all the calls to  `unwrap()` in the codebase, which made me found a couple of places where it wasn't needed, and could be improved. I also noticed we don't have dependabot updates for the test262 submodule and the interner dependencies, so I added those.

I added lints so that no new unwraps are added.

.github/dependabot.yml

@@ -1,30 +1,38 @@
 version: 2
 updates:
-  - package-ecosystem: "npm"
+  - package-ecosystem: npm
-    directory: "/"
+    directory: /
     schedule:
-      interval: "daily"
+      interval: daily
-  - package-ecosystem: "github-actions"
+  - package-ecosystem: github-actions
-    directory: "/"
+    directory: /
     schedule:
-      interval: "daily"
+      interval: daily
-  - package-ecosystem: "cargo"
+  - package-ecosystem: cargo
-    directory: "/"
+    directory: /
     schedule:
-      interval: "daily"
+      interval: daily
-  - package-ecosystem: "cargo"
+  - package-ecosystem: cargo
-    directory: "/boa/"
+    directory: /boa/
     schedule:
-      interval: "daily"
+      interval: daily
-  - package-ecosystem: "cargo"
+  - package-ecosystem: cargo
-    directory: "/boa_cli/"
+    directory: /boa_cli/
     schedule:
-      interval: "daily"
+      interval: daily
-  - package-ecosystem: "cargo"
+  - package-ecosystem: cargo
-    directory: "/boa_wasm/"
+    directory: /boa_wasm/
     schedule:
-      interval: "daily"
+      interval: daily
-  - package-ecosystem: "cargo"
+  - package-ecosystem: cargo
-    directory: "/boa_tester/"
+    directory: /boa_tester/
     schedule:
-      interval: "daily"
+      interval: daily
+  - package-ecosystem: cargo
+    directory: /boa_interner/
+    schedule:
+      interval: daily
+  - package-ecosystem: gitsubmodule
+    directory: /test262/
+    schedule:
+      interval: weekly

boa/src/builtins/array/mod.rs

@@ -143,27 +143,30 @@ impl Array {
         if number_of_args == 0 {
             // 4.a. Return ! ArrayCreate(0, proto).
             Ok(Self::array_create(0, Some(prototype), context)
-                .unwrap()
+                .expect("this ArrayCreate call must not fail")
                 .into())
         // 5. Else if numberOfArgs = 1, then
         } else if number_of_args == 1 {
             // a. Let len be values[0].
             let len = &args[0];
             // b. Let array be ! ArrayCreate(0, proto).
-            let array = Self::array_create(0, Some(prototype), context).unwrap();
+            let array = Self::array_create(0, Some(prototype), context)
+                .expect("this ArrayCreate call must not fail");
             // c. If Type(len) is not Number, then
             #[allow(clippy::if_not_else)]
             let int_len = if !len.is_number() {
                 // i. Perform ! CreateDataPropertyOrThrow(array, "0", len).
                 array
                     .create_data_property_or_throw(0, len, context)
-                    .unwrap();
+                    .expect("this CreateDataPropertyOrThrow call must not fail");
                 // ii. Let intLen be 1𝔽.
                 1
             // d. Else,
             } else {
                 // i. Let intLen be ! ToUint32(len).
-                let int_len = len.to_u32(context).unwrap();
+                let int_len = len
+                    .to_u32(context)
+                    .expect("this ToUint32 call must not fail");
                 // ii. If SameValueZero(intLen, len) is false, throw a RangeError exception.
                 if !JsValue::same_value_zero(&int_len.into(), len) {
                     return context.throw_range_error("invalid array length");
@@ -171,7 +174,9 @@ impl Array {
                 int_len
             };
             // e. Perform ! Set(array, "length", intLen, true).
-            array.set("length", int_len, true, context).unwrap();
+            array
+                .set("length", int_len, true, context)
+                .expect("this Set call must not fail");
             // f. Return array.
             Ok(array.into())
         // 6. Else,
@@ -189,7 +194,7 @@ impl Array {
                 // iii. Perform ! CreateDataPropertyOrThrow(array, Pk, itemK).
                 array
                     .create_data_property_or_throw(i, item, context)
-                    .unwrap();
+                    .expect("this CreateDataPropertyOrThrow must not fail");
                 // iv. Set k to k + 1.
             }
             // e. Assert: The mathematical value of array's "length" property is numberOfArgs.
@@ -360,8 +365,8 @@ impl Array {
             Ok(
                 c.construct(&[JsValue::new(length)], &c.clone().into(), context)?
                     .as_object()
-                    .cloned()
+                    .expect("constructing an object should always return an object")
-                    .unwrap(),
+                    .clone(),
             )
         } else {
             context.throw_type_error("Symbol.species must be a constructor")
@@ -537,7 +542,7 @@ impl Array {
             if spreadable {
                 // item is guaranteed to be an object since is_concat_spreadable checks it,
                 // so we can call `.unwrap()`
-                let item = item.as_object().unwrap();
+                let item = item.as_object().expect("guaranteed to be an object");
                 // i. Let k be 0.
                 // ii. Let len be ? LengthOfArrayLike(E).
                 let len = item.length_of_array_like(context)?;
@@ -1639,7 +1644,7 @@ impl Array {
                 // v. If shouldFlatten is true
                 if should_flatten {
                     // For `should_flatten` to be true, element must be an object.
-                    let element = element.as_object().unwrap();
+                    let element = element.as_object().expect("must be an object");
 
                     // 1. If depth is +Infinity let newDepth be +Infinity
                     let new_depth = if depth == u64::MAX {

boa/src/builtins/iterable/mod.rs

@@ -83,10 +83,10 @@ pub fn create_iter_result_object(value: JsValue, done: bool, context: &mut Conte
 
     // 3. Perform ! CreateDataPropertyOrThrow(obj, "value", value).
     obj.create_data_property_or_throw("value", value, context)
-        .unwrap();
+        .expect("this CreateDataPropertyOrThrow call must not fail");
     // 4. Perform ! CreateDataPropertyOrThrow(obj, "done", done).
     obj.create_data_property_or_throw("done", done, context)
-        .unwrap();
+        .expect("this CreateDataPropertyOrThrow call must not fail");
     // 5. Return obj.
     obj.into()
 }

boa/src/builtins/json/mod.rs

@@ -170,7 +170,9 @@ impl Json {
                 // ii. For each String P of keys, do
                 for p in keys {
                     // This is safe, because EnumerableOwnPropertyNames with 'key' type only returns strings.
-                    let p = p.as_string().unwrap();
+                    let p = p
+                        .as_string()
+                        .expect("EnumerableOwnPropertyNames only returns strings");
 
                     // 1. Let newElement be ? InternalizeJSONProperty(val, P, reviver).
                     let new_element =
@@ -553,7 +555,12 @@ impl Json {
             // a. Let K be ? EnumerableOwnPropertyNames(value, key).
             let keys = value.enumerable_own_property_names(PropertyNameKind::Key, context)?;
             // Unwrap is safe, because EnumerableOwnPropertyNames with kind "key" only returns string values.
-            keys.iter().map(|v| v.to_string(context).unwrap()).collect()
+            keys.iter()
+                .map(|v| {
+                    v.to_string(context)
+                        .expect("EnumerableOwnPropertyNames only returns strings")
+                })
+                .collect()
         };
 
         // 7. Let partial be a new empty List.

boa/src/builtins/number/mod.rs

@@ -343,7 +343,10 @@ impl Number {
     fn round_to_precision(digits: &mut String, precision: usize) -> bool {
         if digits.len() > precision {
             let to_round = digits.split_off(precision);
-            let mut digit = digits.pop().unwrap() as u8;
+            let mut digit = digits
+                .pop()
+                .expect("already checked that lenght is bigger than precision")
+                as u8;
             if let Some(first) = to_round.chars().next() {
                 if first > '4' {
                     digit += 1;
@@ -563,8 +566,9 @@ impl Number {
                 delta *= f64::from(radix);
                 // Write digit.
                 let digit = fraction as u32;
-                frac_buf[fraction_cursor] =
+                frac_buf[fraction_cursor] = std::char::from_digit(digit, u32::from(radix))
-                    std::char::from_digit(digit, u32::from(radix)).unwrap() as u8;
+                    .expect("radix already checked")
+                    as u8;
                 fraction_cursor += 1;
                 // Calculate remainder.
                 fraction -= f64::from(digit);
@@ -582,12 +586,16 @@ impl Number {
                         } else {
                             let c: u8 = frac_buf[fraction_cursor];
                             // Reconstruct digit.
-                            let digit_0 = (c as char).to_digit(10).unwrap();
+                            let digit_0 = (c as char)
+                                .to_digit(10)
+                                .expect("charactre was not a valid digit");
                             if digit_0 + 1 >= u32::from(radix) {
                                 continue;
                             }
                             frac_buf[fraction_cursor] =
-                                std::char::from_digit(digit_0 + 1, u32::from(radix)).unwrap() as u8;
+                                std::char::from_digit(digit_0 + 1, u32::from(radix))
+                                    .expect("digit was not a valid number in the given radix")
+                                    as u8;
                             fraction_cursor += 1;
                         }
                         break;
@@ -601,16 +609,17 @@ impl Number {
         }
 
         // Compute integer digits. Fill unrepresented digits with zero.
-        let mut int_iter = int_buf.iter_mut().enumerate().rev(); //.rev();
+        let mut int_iter = int_buf.iter_mut().enumerate().rev();
         while FloatCore::integer_decode(integer / f64::from(radix)).1 > 0 {
             integer /= f64::from(radix);
-            *int_iter.next().unwrap().1 = b'0';
+            *int_iter.next().expect("integer buffer exhausted").1 = b'0';
         }
 
         loop {
             let remainder = integer % f64::from(radix);
-            *int_iter.next().unwrap().1 =
+            *int_iter.next().expect("integer buffer exhausted").1 =
-                std::char::from_digit(remainder as u32, u32::from(radix)).unwrap() as u8;
+                std::char::from_digit(remainder as u32, u32::from(radix))
+                    .expect("remainder not a digit in the given number") as u8;
             integer = (integer - remainder) / f64::from(radix);
             if integer <= 0f64 {
                 break;
@@ -618,11 +627,11 @@ impl Number {
         }
         // Add sign and terminate string.
         if negative {
-            *int_iter.next().unwrap().1 = b'-';
+            *int_iter.next().expect("integer buffer exhausted").1 = b'-';
         }
         assert!(fraction_cursor < BUF_SIZE);
 
-        let integer_cursor = int_iter.next().unwrap().0 + 1;
+        let integer_cursor = int_iter.next().expect("integer buffer exhausted").0 + 1;
         let fraction_cursor = fraction_cursor + BUF_SIZE / 2;
         String::from_utf8_lossy(&buffer[integer_cursor..fraction_cursor]).into()
     }

boa/src/builtins/object/mod.rs

@@ -605,7 +605,9 @@ impl Object {
             // 3.a. If nextSource is neither undefined nor null, then
             if !source.is_null_or_undefined() {
                 // 3.a.i. Let from be ! ToObject(nextSource).
-                let from = source.to_object(context).unwrap();
+                let from = source
+                    .to_object(context)
+                    .expect("this ToObject call must not fail");
                 // 3.a.ii. Let keys be ? from.[[OwnPropertyKeys]]().
                 let keys = from.__own_property_keys__(context)?;
                 // 3.a.iii. For each element nextKey of keys, do
@@ -925,7 +927,7 @@ impl Object {
 
         // 4. Let closure be a new Abstract Closure with parameters (key, value) that captures
         // obj and performs the following steps when called:
-        let mut closure = FunctionBuilder::closure_with_captures(
+        let closure = FunctionBuilder::closure_with_captures(
             context,
             |_, args, obj, context| {
                 let key = args.get_or_undefined(0);

boa/src/builtins/regexp/mod.rs

@@ -202,7 +202,9 @@ impl RegExp {
         // 6. Else,
         let (p, f) = if let Some(pattern) = pattern_is_regexp {
             let obj = pattern.borrow();
-            let regexp = obj.as_regexp().unwrap();
+            let regexp = obj
+                .as_regexp()
+                .expect("already checked that IsRegExp returns true");
 
             // a. Let P be pattern.[[OriginalSource]].
             // b. If flags is undefined, let F be pattern.[[OriginalFlags]].
@@ -885,11 +887,11 @@ impl RegExp {
 
         // 20. Perform ! CreateDataPropertyOrThrow(A, "index", 𝔽(lastIndex)).
         a.create_data_property_or_throw("index", match_value.start(), context)
-            .unwrap();
+            .expect("this CreateDataPropertyOrThrow call must not fail");
 
         // 21. Perform ! CreateDataPropertyOrThrow(A, "input", S).
         a.create_data_property_or_throw("input", input.clone(), context)
-            .unwrap();
+            .expect("this CreateDataPropertyOrThrow call must not fail");
 
         // 22. Let matchedSubstr be the substring of S from lastIndex to e.
         let matched_substr = if let Some(s) = input.get(match_value.range()) {
@@ -900,7 +902,7 @@ impl RegExp {
 
         // 23. Perform ! CreateDataPropertyOrThrow(A, "0", matchedSubstr).
         a.create_data_property_or_throw(0, matched_substr, context)
-            .unwrap();
+            .expect("this CreateDataPropertyOrThrow call must not fail");
 
         // 24. If R contains any GroupName, then
         // 25. Else,
@@ -924,7 +926,7 @@ impl RegExp {
                     groups
                         .to_object(context)?
                         .create_data_property_or_throw(name, value, context)
-                        .unwrap();
+                        .expect("this CreateDataPropertyOrThrow call must not fail");
                 }
             }
             groups
@@ -935,7 +937,7 @@ impl RegExp {
 
         // 26. Perform ! CreateDataPropertyOrThrow(A, "groups", groups).
         a.create_data_property_or_throw("groups", groups, context)
-            .unwrap();
+            .expect("this CreateDataPropertyOrThrow call must not fail");
 
         // 27. For each integer i such that i ≥ 1 and i ≤ n, in ascending order, do
         for i in 1..=n {
@@ -958,7 +960,7 @@ impl RegExp {
 
             // e. Perform ! CreateDataPropertyOrThrow(A, ! ToString(𝔽(i)), capturedValue).
             a.create_data_property_or_throw(i, captured_value, context)
-                .unwrap();
+                .expect("this CreateDataPropertyOrThrow call must not fail");
         }
 
         // 28. Return A.
@@ -1019,7 +1021,8 @@ impl RegExp {
             rx.set("lastIndex", 0, true, context)?;
 
             // d. Let A be ! ArrayCreate(0).
-            let a = Array::array_create(0, None, context).unwrap();
+            let a =
+                Array::array_create(0, None, context).expect("this ArrayCreate call must not fail");
 
             // e. Let n be 0.
             let mut n = 0;
@@ -1037,7 +1040,7 @@ impl RegExp {
 
                     // 2. Perform ! CreateDataPropertyOrThrow(A, ! ToString(𝔽(n)), matchStr).
                     a.create_data_property_or_throw(n, match_str.clone(), context)
-                        .unwrap();
+                        .expect("this CreateDataPropertyOrThrow call must not fail");
 
                     // 3. If matchStr is the empty String, then
                     if match_str.is_empty() {
@@ -1530,11 +1533,12 @@ impl RegExp {
         )?;
         let splitter = splitter
             .as_object()
-            // todo: remove when we handle realms on `get_prototype_from_constructor` and make `construct` always return a `JsObject`
+            // TODO: remove when we handle realms on `get_prototype_from_constructor` and make
+            // `construct` always return a `JsObject`
             .ok_or_else(|| context.construct_type_error("constructor did not return an object"))?;
 
         // 11. Let A be ! ArrayCreate(0).
-        let a = Array::array_create(0, None, context).unwrap();
+        let a = Array::array_create(0, None, context).expect("this ArrayCreate call must not fail");
 
         // 12. Let lengthA be 0.
         let mut length_a = 0;
@@ -1567,7 +1571,7 @@ impl RegExp {
 
             // c. Perform ! CreateDataPropertyOrThrow(A, "0", S).
             a.create_data_property_or_throw(0, arg_str, context)
-                .unwrap();
+                .expect("this CreateDataPropertyOrThrow call must not fail");
 
             // d. Return A.
             return Ok(a.into());
@@ -1611,7 +1615,7 @@ impl RegExp {
 
                     // 2. Perform ! CreateDataPropertyOrThrow(A, ! ToString(𝔽(lengthA)), T).
                     a.create_data_property_or_throw(length_a, arg_str_substring, context)
-                        .unwrap();
+                        .expect("this CreateDataPropertyOrThrow call must not fail");
 
                     // 3. Set lengthA to lengthA + 1.
                     length_a += 1;
@@ -1642,7 +1646,7 @@ impl RegExp {
 
                         // b. Perform ! CreateDataPropertyOrThrow(A, ! ToString(𝔽(lengthA)), nextCapture).
                         a.create_data_property_or_throw(length_a, next_capture, context)
-                            .unwrap();
+                            .expect("this CreateDataPropertyOrThrow call must not fail");
 
                         // d. Set lengthA to lengthA + 1.
                         length_a += 1;
@@ -1672,7 +1676,7 @@ impl RegExp {
 
         // 21. Perform ! CreateDataPropertyOrThrow(A, ! ToString(𝔽(lengthA)), T).
         a.create_data_property_or_throw(length_a, arg_str_substring, context)
-            .unwrap();
+            .expect("this CreateDataPropertyOrThrow call must not fail");
 
         // 22. Return A.
         Ok(a.into())

boa/src/builtins/string/mod.rs

@@ -1678,7 +1678,7 @@ impl String {
         if separator.is_undefined() {
             // a. Perform ! CreateDataPropertyOrThrow(A, "0", S).
             a.create_data_property_or_throw(0, this_str, context)
-                .unwrap();
+                .expect("this CreateDataPropertyOrThrow call must not fail");
 
             // b. Return A.
             return Ok(a.into());
@@ -1693,7 +1693,7 @@ impl String {
             if !separator_str.is_empty() {
                 // i. Perform ! CreateDataPropertyOrThrow(A, "0", S).
                 a.create_data_property_or_throw(0, this_str, context)
-                    .unwrap();
+                    .expect("this CreateDataPropertyOrThrow call must not fail");
             }
 
             // b. Return A.
@@ -1732,7 +1732,7 @@ impl String {
 
                         // 2. Perform ! CreateDataPropertyOrThrow(A, ! ToString(𝔽(lengthA)), T).
                         a.create_data_property_or_throw(length_a, this_str_substring, context)
-                            .unwrap();
+                            .expect("this CreateDataPropertyOrThrow call must not fail");
 
                         // 3. Set lengthA to lengthA + 1.
                         length_a += 1;
@@ -1763,7 +1763,7 @@ impl String {
 
         // 16. Perform ! CreateDataPropertyOrThrow(A, ! ToString(𝔽(lengthA)), T).
         a.create_data_property_or_throw(length_a, this_str_substring, context)
-            .unwrap();
+            .expect("this CreateDataPropertyOrThrow call must not fail");
 
         // 17. Return A.
         Ok(a.into())
@@ -2013,8 +2013,14 @@ pub(crate) fn get_substitution(
                 // $nn
                 (Some(second), Some(third)) if second_is_digit && third_is_digit => {
                     // The nnth element of captures, where nn is a two-digit decimal number in the range 01 to 99.
-                    let tens = second.to_digit(10).unwrap() as usize;
+                    let tens = second
-                    let units = third.to_digit(10).unwrap() as usize;
+                        .to_digit(10)
+                        .expect("could not convert character to digit after checking it")
+                        as usize;
+                    let units = third
+                        .to_digit(10)
+                        .expect("could not convert character to digit after checking it")
+                        as usize;
                     let nn = 10 * tens + units;
 
                     // If nn ≤ m and the nnth element of captures is undefined, use the empty String instead.
@@ -2034,7 +2040,10 @@ pub(crate) fn get_substitution(
                 // $n
                 (Some(second), _) if second_is_digit => {
                     // The nth element of captures, where n is a single digit in the range 1 to 9.
-                    let n = second.to_digit(10).unwrap() as usize;
+                    let n = second
+                        .to_digit(10)
+                        .expect("could not convert character to digit after checking it")
+                        as usize;
 
                     // If n ≤ m and the nth element of captures is undefined, use the empty String instead.
                     // If n > m, no replacement is done.

boa/src/bytecompiler.rs

@@ -261,7 +261,7 @@ impl<'b> ByteCompiler<'b> {
 
     #[inline]
     fn pop_loop_control_info(&mut self) {
-        let loop_info = self.jump_info.pop().unwrap();
+        let loop_info = self.jump_info.pop().expect("no jump informatiojn found");
 
         assert!(loop_info.kind == JumpControlInfoKind::Loop);
 
@@ -284,7 +284,7 @@ impl<'b> ByteCompiler<'b> {
 
     #[inline]
     fn pop_switch_control_info(&mut self) {
-        let info = self.jump_info.pop().unwrap();
+        let info = self.jump_info.pop().expect("no jump information found");
 
         assert!(info.kind == JumpControlInfoKind::Switch);
 
@@ -296,7 +296,11 @@ impl<'b> ByteCompiler<'b> {
     #[inline]
     fn push_try_control_info(&mut self) {
         if !self.jump_info.is_empty() {
-            let start_address = self.jump_info.last().unwrap().start_address;
+            let start_address = self
+                .jump_info
+                .last()
+                .expect("no jump information found")
+                .start_address;
 
             self.jump_info.push(JumpControlInfo {
                 label: None,
@@ -312,7 +316,7 @@ impl<'b> ByteCompiler<'b> {
     #[inline]
     fn pop_try_control_info(&mut self, finally_start_address: Option<u32>) {
         if !self.jump_info.is_empty() {
-            let mut info = self.jump_info.pop().unwrap();
+            let mut info = self.jump_info.pop().expect("no jump information found");
 
             assert!(info.kind == JumpControlInfoKind::Try);
 
@@ -1219,7 +1223,11 @@ impl<'b> ByteCompiler<'b> {
                     self.emit_opcode(Opcode::TryEnd);
                     self.emit(Opcode::FinallySetJump, &[start_address]);
                     let label = self.jump();
-                    self.jump_info.last_mut().unwrap().try_continues.push(label);
+                    self.jump_info
+                        .last_mut()
+                        .expect("no jump information found")
+                        .try_continues
+                        .push(label);
                 } else {
                     let mut items = self
                         .jump_info
@@ -1264,7 +1272,11 @@ impl<'b> ByteCompiler<'b> {
                 }
                 let label = self.jump();
                 if node.label().is_none() {
-                    self.jump_info.last_mut().unwrap().breaks.push(label);
+                    self.jump_info
+                        .last_mut()
+                        .expect("no jump information found")
+                        .breaks
+                        .push(label);
                 } else {
                     for info in self.jump_info.iter_mut().rev() {
                         if info.label == node.label() {

boa/src/lib.rs

@@ -10,6 +10,7 @@
     html_logo_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg",
     html_favicon_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg"
 )]
+#![cfg_attr(not(test), forbid(clippy::unwrap_used))]
 #![warn(
     clippy::perf,
     clippy::single_match_else,

boa/src/object/internal_methods/array.rs

@@ -35,21 +35,85 @@ pub(crate) fn array_exotic_define_own_property(
         PropertyKey::String(ref s) if s == "length" => {
             // a. Return ? ArraySetLength(A, Desc).
 
-            // Abstract operation `ArraySetLength ( A, Desc )`
+            array_set_length(obj, desc, context)
-            //
+        }
-            // https://tc39.es/ecma262/#sec-arraysetlength
+        // 3. Else if P is an array index, then
+        PropertyKey::Index(index) if index < u32::MAX => {
+            // a. Let oldLenDesc be OrdinaryGetOwnProperty(A, "length").
+            let old_len_desc = super::ordinary_get_own_property(obj, &"length".into(), context)?
+                .expect("the property descriptor must exist");
+
+            // b. Assert: ! IsDataDescriptor(oldLenDesc) is true.
+            debug_assert!(old_len_desc.is_data_descriptor());
+
+            // c. Assert: oldLenDesc.[[Configurable]] is false.
+            debug_assert!(!old_len_desc.expect_configurable());
+
+            // d. Let oldLen be oldLenDesc.[[Value]].
+            // e. Assert: oldLen is a non-negative integral Number.
+            // f. Let index be ! ToUint32(P).
+            let old_len = old_len_desc
+                .expect_value()
+                .to_u32(context)
+                .expect("this ToUint32 call must not fail");
+
+            // g. If index ≥ oldLen and oldLenDesc.[[Writable]] is false, return false.
+            if index >= old_len && !old_len_desc.expect_writable() {
+                return Ok(false);
+            }
+
+            // h. Let succeeded be ! OrdinaryDefineOwnProperty(A, P, Desc).
+            if super::ordinary_define_own_property(obj, key, desc, context)? {
+                // j. If index ≥ oldLen, then
+                if index >= old_len {
+                    // i. Set oldLenDesc.[[Value]] to index + 1𝔽.
+                    let old_len_desc = PropertyDescriptor::builder()
+                        .value(index + 1)
+                        .maybe_writable(old_len_desc.writable())
+                        .maybe_enumerable(old_len_desc.enumerable())
+                        .maybe_configurable(old_len_desc.configurable());
+
+                    // ii. Set succeeded to OrdinaryDefineOwnProperty(A, "length", oldLenDesc).
+                    let succeeded = super::ordinary_define_own_property(
+                        obj,
+                        "length".into(),
+                        old_len_desc.into(),
+                        context,
+                    )?;
+
+                    // iii. Assert: succeeded is true.
+                    debug_assert!(succeeded);
+                }
 
+                // k. Return true.
+                Ok(true)
+            } else {
+                // i. If succeeded is false, return false.
+                Ok(false)
+            }
+        }
+        // 4. Return OrdinaryDefineOwnProperty(A, P, Desc).
+        _ => super::ordinary_define_own_property(obj, key, desc, context),
+    }
+}
+
+/// Abstract operation `ArraySetLength ( A, Desc )`
+///
+/// More information:
+///  - [ECMAScript reference][spec]
+///
+/// [spec]: https://tc39.es/ecma262/#sec-arraysetlength
+fn array_set_length(
+    obj: &JsObject,
+    desc: PropertyDescriptor,
+    context: &mut Context,
+) -> JsResult<bool> {
     // 1. If Desc.[[Value]] is absent, then
     let new_len_val = match desc.value() {
         Some(value) => value,
         _ => {
             // a. Return OrdinaryDefineOwnProperty(A, "length", Desc).
-                    return super::ordinary_define_own_property(
+            return super::ordinary_define_own_property(obj, "length".into(), desc, context);
-                        obj,
-                        "length".into(),
-                        desc,
-                        context,
-                    );
         }
     };
 
@@ -74,8 +138,8 @@ pub(crate) fn array_exotic_define_own_property(
         .maybe_configurable(desc.configurable());
 
     // 7. Let oldLenDesc be OrdinaryGetOwnProperty(A, "length").
-            let old_len_desc =
+    let old_len_desc = super::ordinary_get_own_property(obj, &"length".into(), context)?
-                super::ordinary_get_own_property(obj, &"length".into(), context)?.unwrap();
+        .expect("the property descriptor must exist");
 
     // 8. Assert: ! IsDataDescriptor(oldLenDesc) is true.
     debug_assert!(old_len_desc.is_data_descriptor());
@@ -125,7 +189,7 @@ pub(crate) fn array_exotic_define_own_property(
         new_len_desc.clone().build(),
         context,
     )
-            .unwrap()
+    .expect("this OrdinaryDefineOwnProperty call must not fail")
     {
         return Ok(false);
     }
@@ -163,7 +227,7 @@ pub(crate) fn array_exotic_define_own_property(
                 new_len_desc.build(),
                 context,
             )
-                    .unwrap();
+            .expect("this OrdinaryDefineOwnProperty call must not fail");
 
             // iv. Return false.
             return Ok(false);
@@ -179,7 +243,8 @@ pub(crate) fn array_exotic_define_own_property(
             "length".into(),
             PropertyDescriptor::builder().writable(false).build(),
             context,
-                )?;
+        )
+        .expect("this OrdinaryDefineOwnProperty call must not fail");
 
         // b. Assert: succeeded is true.
         debug_assert!(succeeded);
@@ -188,61 +253,3 @@ pub(crate) fn array_exotic_define_own_property(
     // 19. Return true.
     Ok(true)
 }
-
-        // 3. Else if P is an array index, then
-        PropertyKey::Index(index) if index < u32::MAX => {
-            // a. Let oldLenDesc be OrdinaryGetOwnProperty(A, "length").
-            let old_len_desc =
-                super::ordinary_get_own_property(obj, &"length".into(), context)?.unwrap();
-
-            // b. Assert: ! IsDataDescriptor(oldLenDesc) is true.
-            debug_assert!(old_len_desc.is_data_descriptor());
-
-            // c. Assert: oldLenDesc.[[Configurable]] is false.
-            debug_assert!(!old_len_desc.expect_configurable());
-
-            // d. Let oldLen be oldLenDesc.[[Value]].
-            // e. Assert: oldLen is a non-negative integral Number.
-            // f. Let index be ! ToUint32(P).
-            let old_len = old_len_desc.expect_value().to_u32(context).unwrap();
-
-            // g. If index ≥ oldLen and oldLenDesc.[[Writable]] is false, return false.
-            if index >= old_len && !old_len_desc.expect_writable() {
-                return Ok(false);
-            }
-
-            // h. Let succeeded be ! OrdinaryDefineOwnProperty(A, P, Desc).
-            if super::ordinary_define_own_property(obj, key, desc, context)? {
-                // j. If index ≥ oldLen, then
-                if index >= old_len {
-                    // i. Set oldLenDesc.[[Value]] to index + 1𝔽.
-                    let old_len_desc = PropertyDescriptor::builder()
-                        .value(index + 1)
-                        .maybe_writable(old_len_desc.writable())
-                        .maybe_enumerable(old_len_desc.enumerable())
-                        .maybe_configurable(old_len_desc.configurable());
-
-                    // ii. Set succeeded to OrdinaryDefineOwnProperty(A, "length", oldLenDesc).
-                    let succeeded = super::ordinary_define_own_property(
-                        obj,
-                        "length".into(),
-                        old_len_desc.into(),
-                        context,
-                    )
-                    .unwrap();
-
-                    // iii. Assert: succeeded is true.
-                    debug_assert!(succeeded);
-                }
-
-                // k. Return true.
-                Ok(true)
-            } else {
-                // i. If succeeded is false, return false.
-                Ok(false)
-            }
-        }
-        // 4. Return OrdinaryDefineOwnProperty(A, P, Desc).
-        _ => super::ordinary_define_own_property(obj, key, desc, context),
-    }
-}

boa/src/object/jsobject.rs

@@ -211,7 +211,9 @@ impl JsObject {
     {
         let object = self.borrow();
         if object.is::<T>() {
-            Some(Ref::map(object, |x| x.downcast_ref::<T>().unwrap()))
+            Some(Ref::map(object, |x| {
+                x.downcast_ref::<T>().expect("downcasting reference failed")
+            }))
         } else {
             None
         }
@@ -231,7 +233,10 @@ impl JsObject {
     {
         let object = self.borrow_mut();
         if object.is::<T>() {
-            Some(RefMut::map(object, |x| x.downcast_mut::<T>().unwrap()))
+            Some(RefMut::map(object, |x| {
+                x.downcast_mut::<T>()
+                    .expect("downcasting mutable reference failed")
+            }))
         } else {
             None
         }

boa/src/object/mod.rs

@@ -1238,7 +1238,7 @@ where
 #[derive(Debug)]
 pub struct FunctionBuilder<'context> {
     context: &'context mut Context,
-    function: Option<Function>,
+    function: Function,
     name: JsString,
     length: usize,
 }
@@ -1249,10 +1249,10 @@ impl<'context> FunctionBuilder<'context> {
     pub fn native(context: &'context mut Context, function: NativeFunctionSignature) -> Self {
         Self {
             context,
-            function: Some(Function::Native {
+            function: Function::Native {
                 function,
                 constructor: false,
-            }),
+            },
             name: JsString::default(),
             length: 0,
         }
@@ -1266,11 +1266,11 @@ impl<'context> FunctionBuilder<'context> {
     {
         Self {
             context,
-            function: Some(Function::Closure {
+            function: Function::Closure {
                 function: Box::new(move |this, args, _, context| function(this, args, context)),
                 constructor: false,
                 captures: Captures::new(()),
-            }),
+            },
             name: JsString::default(),
             length: 0,
         }
@@ -1294,7 +1294,7 @@ impl<'context> FunctionBuilder<'context> {
     {
         Self {
             context,
-            function: Some(Function::Closure {
+            function: Function::Closure {
                 function: Box::new(move |this, args, captures: Captures, context| {
                     let mut captures = captures.as_mut_any();
                     let captures = captures.downcast_mut::<C>().ok_or_else(|| {
@@ -1304,7 +1304,7 @@ impl<'context> FunctionBuilder<'context> {
                 }),
                 constructor: false,
                 captures: Captures::new(captures),
-            }),
+            },
             name: JsString::default(),
             length: 0,
         }
@@ -1314,7 +1314,7 @@ impl<'context> FunctionBuilder<'context> {
     ///
     /// The default is `""` (empty string).
     #[inline]
-    pub fn name<N>(&mut self, name: N) -> &mut Self
+    pub fn name<N>(mut self, name: N) -> Self
     where
         N: AsRef<str>,
     {
@@ -1328,7 +1328,7 @@ impl<'context> FunctionBuilder<'context> {
     ///
     /// The default is `0`.
     #[inline]
-    pub fn length(&mut self, length: usize) -> &mut Self {
+    pub fn length(mut self, length: usize) -> Self {
         self.length = length;
         self
     }
@@ -1337,40 +1337,47 @@ impl<'context> FunctionBuilder<'context> {
     ///
     /// The default is `false`.
     #[inline]
-    pub fn constructor(&mut self, yes: bool) -> &mut Self {
+    pub fn constructor(mut self, yes: bool) -> Self {
-        match self.function.as_mut() {
+        match self.function {
-            Some(Function::Native { constructor, .. } | Function::Closure { constructor, .. }) => {
+            Function::Native {
+                ref mut constructor,
+                ..
+            }
+            | Function::Closure {
+                ref mut constructor,
+                ..
+            } => {
                 *constructor = yes;
             }
-            _ => unreachable!(),
+            Function::VmOrdinary { .. } => unreachable!("function must be native or closure"),
         }
         self
     }
 
     /// Build the function object.
     #[inline]
-    pub fn build(&mut self) -> JsObject {
+    pub fn build(self) -> JsObject {
         let function = JsObject::from_proto_and_data(
             self.context
                 .standard_objects()
                 .function_object()
                 .prototype(),
-            ObjectData::function(self.function.take().unwrap()),
+            ObjectData::function(self.function),
         );
         let property = PropertyDescriptor::builder()
             .writable(false)
             .enumerable(false)
             .configurable(true);
         function.insert_property("length", property.clone().value(self.length));
-        function.insert_property("name", property.value(self.name.clone()));
+        function.insert_property("name", property.value(self.name));
 
         function
     }
 
     /// Initializes the `Function.prototype` function object.
-    pub(crate) fn build_function_prototype(&mut self, object: &JsObject) {
+    pub(crate) fn build_function_prototype(self, object: &JsObject) {
         let mut object = object.borrow_mut();
-        object.data = ObjectData::function(self.function.take().unwrap());
+        object.data = ObjectData::function(self.function);
         object.set_prototype(self.context.standard_objects().object_object().prototype());
 
         let property = PropertyDescriptor::builder()

boa/src/string.rs

@@ -213,8 +213,8 @@ impl Inner {
         // of the string array.
         let inner_layout = Layout::new::<Self>();
         let (layout, offset) = inner_layout
-            .extend(Layout::array::<u8>(s.len()).unwrap())
+            .extend(Layout::array::<u8>(s.len()).expect("failed to create memory layout"))
-            .unwrap();
+            .expect("failed to extend memory layout");
 
         let inner = unsafe {
             let inner = alloc(layout).cast::<Self>();
@@ -253,8 +253,8 @@ impl Inner {
         // of the string array.
         let inner_layout = Layout::new::<Self>();
         let (layout, offset) = inner_layout
-            .extend(Layout::array::<u8>(total_string_size).unwrap())
+            .extend(Layout::array::<u8>(total_string_size).expect("failed to create memory layout"))
-            .unwrap();
+            .expect("failed to extend memory layout");
 
         let inner = unsafe {
             let inner = alloc(layout).cast::<Self>();
@@ -292,8 +292,8 @@ impl Inner {
 
         let inner_layout = Layout::new::<Self>();
         let (layout, _offset) = inner_layout
-            .extend(Layout::array::<u8>(len).unwrap())
+            .extend(Layout::array::<u8>(len).expect("failed to create memory layout"))
-            .unwrap();
+            .expect("failed to extend memory layout");
 
         dealloc(x.as_ptr().cast::<_>(), layout);
     }

boa/src/syntax/lexer/cursor.rs

@@ -204,7 +204,10 @@ where
                 return Ok(());
             } else if let Some(ch) = self.peek_char()? {
                 for _ in 0..utf8_len(ch) {
-                    buf.push(self.next_byte()?.unwrap());
+                    buf.push(
+                        self.next_byte()?
+                            .expect("already checked that the next character exists"),
+                    );
                 }
             } else {
                 // next_is_pred will return false if the next value is None so the None case should already be handled.

boa/src/syntax/lexer/identifier.rs

@@ -154,7 +154,10 @@ impl Identifier {
 
             if Self::is_identifier_start(ch) {
                 contains_escaped_chars = true;
-                String::from(char::try_from(ch).unwrap())
+                String::from(
+                    char::try_from(ch)
+                        .expect("all identifier starts must be convertible to strings"),
+                )
             } else {
                 return Err(Error::Syntax("invalid identifier start".into(), start_pos));
             }
@@ -185,7 +188,7 @@ impl Identifier {
                 _ => break,
             };
 
-            identifier_name.push(char::try_from(ch).unwrap());
+            identifier_name.push(char::try_from(ch).expect("checked character value"));
         }
 
         Ok((identifier_name, contains_escaped_chars))

boa/src/syntax/lexer/template.rs

@@ -20,7 +20,8 @@ use serde::{Deserialize, Serialize};
 pub struct TemplateString {
     /// The template string of template literal with argument `raw` true.
     raw: Sym,
-    /// The start position of the template string. Used to make lexer error if `to_owned_cooked` failed.
+    /// The start position of the template string. Used to make lexer error if `to_owned_cooked`
+    /// failed.
     start_pos: Position,
 }
 
@@ -40,7 +41,8 @@ impl TemplateString {
         self.raw
     }
 
-    /// Creats a new cooked template string. Returns a lexer error if it fails to cook the template string.
+    /// Creats a new cooked template string. Returns a lexer error if it fails to cook the
+    /// template string.
     ///
     /// More information:
     ///  - [ECMAScript reference][spec]
@@ -70,8 +72,8 @@ impl TemplateString {
                 }
                 Some(ch) => {
                     // The caller guarantees that sequences '`' and '${' never appear
-                    // LineTerminatorSequence <CR> <LF> is consumed by `cursor.next_char()` and returns <LF>,
+                    // LineTerminatorSequence <CR> <LF> is consumed by `cursor.next_char()` and
-                    // which matches the TV of <CR> <LF>
+                    // returns <LF>, which matches the TV of <CR> <LF>
                     buf.push_code_point(ch);
                 }
                 None => break,
@@ -119,7 +121,8 @@ impl<R> Tokenizer<R> for TemplateLiteral {
             })?;
 
             match ch {
-                0x0060 /* ` */ => {
+                // `
+                0x0060 => {
                     let raw = buf.to_string_lossy();
                     let raw_sym = interner.get_or_intern(raw);
                     let template_string = TemplateString::new(raw_sym, start_pos);
@@ -129,7 +132,8 @@ impl<R> Tokenizer<R> for TemplateLiteral {
                         Span::new(start_pos, cursor.pos()),
                     ));
                 }
-                0x0024 /* $ */ if cursor.next_is(b'{')? => {
+                // $
+                0x0024 if cursor.next_is(b'{')? => {
                     let raw = buf.to_string_lossy();
                     let raw_sym = interner.get_or_intern(raw);
                     let template_string = TemplateString::new(raw_sym, start_pos);
@@ -139,7 +143,8 @@ impl<R> Tokenizer<R> for TemplateLiteral {
                         Span::new(start_pos, cursor.pos()),
                     ));
                 }
-                0x005C /* \ */ => {
+                // \
+                0x005C => {
                     let escape_ch = cursor.peek()?.ok_or_else(|| {
                         Error::from(io::Error::new(
                             ErrorKind::UnexpectedEof,
@@ -149,7 +154,11 @@ impl<R> Tokenizer<R> for TemplateLiteral {
 
                     buf.push(u16::from(b'\\'));
                     match escape_ch {
-                        b'`' | b'$' | b'\\' => buf.push(u16::from(cursor.next_byte()?.unwrap())),
+                        b'`' | b'$' | b'\\' => {
+                            let next_byte =
+                                cursor.next_byte()?.expect("already checked next character");
+                            buf.push(u16::from(next_byte));
+                        }
                         _ => continue,
                     }
                 }

boa/src/syntax/parser/error.rs

@@ -134,7 +134,10 @@ impl fmt::Display for ParseError {
                 f,
                 "expected {}, got '{found}' in {context} at line {}, col {}",
                 if expected.len() == 1 {
-                    format!("token '{}'", expected.first().unwrap())
+                    format!(
+                        "token '{}'",
+                        expected.first().expect("already checked that length is 1")
+                    )
                 } else {
                     format!(
                         "one of {}",

boa/src/syntax/parser/expression/mod.rs

@@ -489,10 +489,6 @@ where
     fn parse(self, cursor: &mut Cursor<R>, interner: &mut Interner) -> ParseResult {
         let _timer = BoaProfiler::global().start_event("Relation Expression", "Parsing");
 
-        if None::<InputElement>.is_some() {
-            cursor.set_goal(None::<InputElement>.unwrap());
-        }
-
         let mut lhs =
             ShiftExpression::new(self.allow_yield, self.allow_await).parse(cursor, interner)?;
         while let Some(tok) = cursor.peek(0, interner)? {

boa/src/syntax/parser/statement/iteration/for_statement.rs

@@ -102,9 +102,9 @@ where
             ),
         };
 
-        match cursor.peek(0, interner)? {
+        match (init.as_ref(), cursor.peek(0, interner)?) {
-            Some(tok) if tok.kind() == &TokenKind::Keyword(Keyword::In) && init.is_some() => {
+            (Some(init), Some(tok)) if tok.kind() == &TokenKind::Keyword(Keyword::In) => {
-                let init = node_to_iterable_loop_initializer(&init.unwrap(), init_position)?;
+                let init = node_to_iterable_loop_initializer(init, init_position)?;
 
                 let _next = cursor.next(interner)?;
                 let expr = Expression::new(None, true, self.allow_yield, self.allow_await)
@@ -125,8 +125,8 @@ where
 
                 return Ok(ForInLoop::new(init, expr, body).into());
             }
-            Some(tok) if tok.kind() == &TokenKind::Keyword(Keyword::Of) && init.is_some() => {
+            (Some(init), Some(tok)) if tok.kind() == &TokenKind::Keyword(Keyword::Of) => {
-                let init = node_to_iterable_loop_initializer(&init.unwrap(), init_position)?;
+                let init = node_to_iterable_loop_initializer(init, init_position)?;
 
                 let _next = cursor.next(interner)?;
                 let iterable = Expression::new(None, true, self.allow_yield, self.allow_await)

boa/src/syntax/parser/statement/mod.rs

@@ -202,12 +202,9 @@ where
                 // Labelled Statement check
                 cursor.set_goal(InputElement::Div);
                 let tok = cursor.peek(1, interner)?;
-                if tok.is_some()
+
-                    && matches!(
+                if let Some(tok) = tok {
-                        tok.unwrap().kind(),
+                    if matches!(tok.kind(), TokenKind::Punctuator(Punctuator::Colon)) {
-                        TokenKind::Punctuator(Punctuator::Colon)
-                    )
-                {
                         return LabelledStatement::new(
                             self.allow_yield,
                             self.allow_await,
@@ -216,6 +213,7 @@ where
                         .parse(cursor, interner)
                         .map(Node::from);
                     }
+                }
 
                 ExpressionStatement::new(self.allow_yield, self.allow_await).parse(cursor, interner)
             }

boa/src/value/operations.rs

@@ -541,7 +541,8 @@ impl JsValue {
                             } else {
                                 y.ceil()
                             };
-                            (*x < JsBigInt::try_from(n).unwrap()).into()
+                            (*x < JsBigInt::try_from(n).expect("invalid conversion to BigInt"))
+                                .into()
                         }
                         (Numeric::Number(x), Numeric::BigInt(ref y)) => {
                             if x.is_nan() {
@@ -555,7 +556,8 @@ impl JsValue {
                             } else {
                                 x.ceil()
                             };
-                            (JsBigInt::try_from(n).unwrap() < *y).into()
+                            (JsBigInt::try_from(n).expect("invalid conversion to BigInt") < *y)
+                                .into()
                         }
                     },
                 }

boa/src/vm/code_block.rs

@@ -136,7 +136,7 @@ impl CodeBlock {
     ///
     /// Returns an empty `String` if no operands are present.
     pub(crate) fn instruction_operands(&self, pc: &mut usize) -> String {
-        let opcode: Opcode = self.code[*pc].try_into().unwrap();
+        let opcode: Opcode = self.code[*pc].try_into().expect("invalid opcode");
         *pc += size_of::<Opcode>();
         match opcode {
             Opcode::PushInt8 => {
@@ -313,7 +313,7 @@ impl ToInternedString for CodeBlock {
         let mut pc = 0;
         let mut count = 0;
         while pc < self.code.len() {
-            let opcode: Opcode = self.code[pc].try_into().unwrap();
+            let opcode: Opcode = self.code[pc].try_into().expect("invalid opcode");
             let operands = self.instruction_operands(&mut pc);
             f.push_str(&format!(
                 "    {pc:06}    {count:04}    {:<27}\n{operands}",
@@ -406,7 +406,7 @@ impl JsVmFunction {
 
         prototype
             .define_property_or_throw("constructor", constructor_property, context)
-            .unwrap();
+            .expect("failed to define the constructor property of the function");
 
         let prototype_property = PropertyDescriptor::builder()
             .value(prototype)
@@ -417,13 +417,13 @@ impl JsVmFunction {
 
         constructor
             .define_property_or_throw("prototype", prototype_property, context)
-            .unwrap();
+            .expect("failed to define the prototype property of the function");
         constructor
             .define_property_or_throw("name", name_property, context)
-            .unwrap();
+            .expect("failed to define the name property of the function");
         constructor
             .define_property_or_throw("length", length_property, context)
-            .unwrap();
+            .expect("failed to define the length property of the function");
 
         constructor
     }
@@ -462,7 +462,7 @@ impl JsObject {
 
         let body = {
             let object = self.borrow();
-            let function = object.as_function().unwrap();
+            let function = object.as_function().expect("not a function");
 
             match function {
                 Function::Native {
@@ -633,7 +633,7 @@ impl JsObject {
 
         let body = {
             let object = self.borrow();
-            let function = object.as_function().unwrap();
+            let function = object.as_function().expect("not a function");
 
             match function {
                 Function::Native { function, .. } => FunctionBody::Native {

boa/src/vm/mod.rs

@@ -55,7 +55,7 @@ impl Vm {
     #[inline]
     #[track_caller]
     pub(crate) fn pop(&mut self) -> JsValue {
-        self.stack.pop().unwrap()
+        self.stack.pop().expect("stack was empty")
     }
 
     #[track_caller]
@@ -66,14 +66,24 @@ impl Vm {
         value
     }
 
+    /// Retrieves the VM frame
+    ///
+    /// # Panics
+    ///
+    /// If there is no frame, then this will panic.
     #[inline]
     pub(crate) fn frame(&self) -> &CallFrame {
-        self.frame.as_ref().unwrap()
+        self.frame.as_ref().expect("no frame found")
     }
 
+    /// Retrieves the VM frame mutably
+    ///
+    /// # Panics
+    ///
+    /// If there is no frame, then this will panic.
     #[inline]
     pub(crate) fn frame_mut(&mut self) -> &mut CallFrame {
-        self.frame.as_mut().unwrap()
+        self.frame.as_mut().expect("no frame found")
     }
 
     #[inline]
@@ -661,10 +671,10 @@ impl Context {
                 let excluded_key_count = self.vm.read::<u32>();
                 let mut excluded_keys = Vec::with_capacity(excluded_key_count as usize);
                 for _ in 0..excluded_key_count {
-                    excluded_keys.push(self.vm.pop().as_string().unwrap().clone());
+                    excluded_keys.push(self.vm.pop().as_string().expect("not a string").clone());
                 }
                 let value = self.vm.pop();
-                let object = value.as_object().unwrap();
+                let object = value.as_object().expect("not an object");
                 let source = self.vm.pop();
                 object.copy_data_properties(&source, excluded_keys, self)?;
                 self.vm.push(value);
@@ -989,7 +999,7 @@ impl Context {
                 let done = self.vm.pop();
                 let next_function = self.vm.pop();
                 let iterator = self.vm.pop();
-                if !done.as_boolean().unwrap() {
+                if !done.as_boolean().expect("not a boolean") {
                     let iterator_record = IteratorRecord::new(iterator, next_function);
                     iterator_record.close(Ok(JsValue::Null), self)?;
                 }
@@ -1075,7 +1085,8 @@ impl Context {
                         args.push(self.vm.pop());
                     }
                     let array = Array::new_array(self);
-                    Array::add_to_array_object(&array, &args, self).unwrap();
+                    Array::add_to_array_object(&array, &args, self)
+                        .expect("could not add to array object");
                     self.vm.push(array);
                 } else {
                     self.vm.pop();
@@ -1139,7 +1150,13 @@ impl Context {
         while self.vm.frame().pc < self.vm.frame().code.code.len() {
             let result = if self.vm.trace {
                 let mut pc = self.vm.frame().pc;
-                let opcode: Opcode = self.vm.frame().code.read::<u8>(pc).try_into().unwrap();
+                let opcode: Opcode = self
+                    .vm
+                    .frame()
+                    .code
+                    .read::<u8>(pc)
+                    .try_into()
+                    .expect("invalid opcode");
                 let operands = self.vm.frame().code.instruction_operands(&mut pc);
 
                 let instant = Instant::now();

boa_cli/src/helper.rs

@@ -137,7 +137,7 @@ impl Highlighter for LineHighlighter {
             (?P<op>[+\-/*%~^!&|=<>;:]) |
             (?P<number>0[bB][01](_?[01])*n?|0[oO][0-7](_?[0-7])*n?|0[xX][0-9a-fA-F](_?[0-9a-fA-F])*n?|(([0-9](_?[0-9])*\.([0-9](_?[0-9])*)?)|(([0-9](_?[0-9])*)?\.[0-9](_?[0-9])*)|([0-9](_?[0-9])*))([eE][+-]?[0-9](_?[0-9])*)?n?)"#,
         )
-        .unwrap();
+        .expect("could not compile regular expression");
 
         coloured = reg
             .replace_all(&coloured, |caps: &Captures<'_>| {

boa_cli/src/main.rs

@@ -2,6 +2,7 @@
     html_logo_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg",
     html_favicon_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg"
 )]
+#![cfg_attr(not(test), deny(clippy::unwrap_used))]
 #![warn(
     clippy::perf,
     clippy::single_match_else,
@@ -168,9 +169,16 @@ where
         match arg {
             Some(format) => match format {
                 DumpFormat::Debug => println!("{ast:#?}"),
-                DumpFormat::Json => println!("{}", serde_json::to_string(&ast).unwrap()),
+                DumpFormat::Json => println!(
+                    "{}",
+                    serde_json::to_string(&ast).expect("could not convert AST to a JSON string")
+                ),
                 DumpFormat::JsonPretty => {
-                    println!("{}", serde_json::to_string_pretty(&ast).unwrap());
+                    println!(
+                        "{}",
+                        serde_json::to_string_pretty(&ast)
+                            .expect("could not convert AST to a pretty JSON string")
+                    );
                 }
             },
             // Default ast dumping format.
@@ -256,7 +264,9 @@ pub fn main() -> Result<(), std::io::Error> {
             }
         }
 
-        editor.save_history(CLI_HISTORY).unwrap();
+        editor
+            .save_history(CLI_HISTORY)
+            .expect("could not save CLI history");
     }
 
     Ok(())

boa_interner/src/lib.rs

@@ -12,6 +12,7 @@
     html_logo_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg",
     html_favicon_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg"
 )]
+#![cfg_attr(not(test), forbid(clippy::unwrap_used))]
 #![warn(
     clippy::perf,
     clippy::single_match_else,

boa_tester/src/main.rs

@@ -2,6 +2,11 @@
 //!
 //! This crate will run the full ECMAScript test suite (Test262) and report compliance of the
 //! `boa` context.
+#![doc(
+    html_logo_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg",
+    html_favicon_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg"
+)]
+#![cfg_attr(not(test), deny(clippy::unwrap_used))]
 #![warn(
     clippy::perf,
     clippy::single_match_else,

boa_unicode/src/lib.rs

@@ -10,6 +10,7 @@
     html_logo_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg",
     html_favicon_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg"
 )]
+#![cfg_attr(not(test), forbid(clippy::unwrap_used))]
 #![warn(
     clippy::perf,
     clippy::single_match_else,

boa_wasm/src/lib.rs

@@ -2,6 +2,7 @@
     html_logo_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg",
     html_favicon_url = "https://raw.githubusercontent.com/boa-dev/boa/main/assets/logo.svg"
 )]
+#![cfg_attr(not(test), forbid(clippy::unwrap_used))]
 #![warn(
     clippy::perf,
     clippy::single_match_else,