fix(es/parser): Make let a reserved word in strict mode (#4113)

swc-project · Mar 22, 2022 · 9a8fc27 · 9a8fc27 · github-actions · Mar 22, 2022
1 parent 39507b0
commit 9a8fc27
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Showing 5 changed files with 21 additions and 21 deletions.
diff --git a/crates/swc_ecma_parser/src/parser/expr.rs b/crates/swc_ecma_parser/src/parser/expr.rs
@@ -357,27 +357,12 @@ impl<'a, I: Tokens> Parser<I> {
             || (self.input.syntax().typescript() && is_one_of!(self, IdentRef, "await"))
             || is!(self, IdentRef)
         {
-            // TODO: Handle [Yield, Await]
             let id = self.parse_ident_name()?;
-            match id.sym {
-                //                    js_word!("eval") | js_word!("arguments") => {
-                //                        self.emit_err(id.span,
-                // SyntaxError::EvalAndArgumentsInStrict)
-                // }
-                js_word!("yield")
-                | js_word!("static")
-                | js_word!("implements")
-                | js_word!("let")
-                | js_word!("package")
-                | js_word!("private")
-                | js_word!("protected")
-                | js_word!("public") => {
-                    self.emit_strict_mode_err(
-                        self.input.prev_span(),
-                        SyntaxError::InvalidIdentInStrict,
-                    );
-                }
-                _ => {}
+            if id.is_reserved_in_strict_mode(self.ctx().module && !self.ctx().in_declare) {
+                self.emit_strict_mode_err(
+                    self.input.prev_span(),
+                    SyntaxError::InvalidIdentInStrict,
+                );
             }
 
             if can_be_arrow && id.sym == js_word!("async") && is!(self, BindingIdent) {

diff --git a/crates/swc_ecma_parser/src/parser/ident.rs b/crates/swc_ecma_parser/src/parser/ident.rs
@@ -115,10 +115,10 @@ impl<'a, I: Tokens> Parser<I> {
                     p.emit_err(p.input.prev_span(), SyntaxError::InvalidIdentInStrict);
                 }
                 Word::Keyword(Keyword::Yield)
+                | Word::Keyword(Keyword::Let)
                 | Word::Ident(js_word!("static"))
                 | Word::Ident(js_word!("implements"))
                 | Word::Ident(js_word!("interface"))
-                | Word::Ident(js_word!("let"))
                 | Word::Ident(js_word!("package"))
                 | Word::Ident(js_word!("private"))
                 | Word::Ident(js_word!("protected"))

diff --git a/crates/swc_ecma_parser/tests/typescript-errors/issue-1391/case2/input.ts.stderr b/crates/swc_ecma_parser/tests/typescript-errors/issue-1391/case2/input.ts.stderr
@@ -1,4 +1,10 @@
 
+  x 'implements', 'interface', 'let', 'package', 'private', 'protected',  'public', 'static', or 'yield' cannot be used as an identifier in strict mode
+   ,-[$DIR/tests/typescript-errors/issue-1391/case2/input.ts:2:5]
+ 2 | let b = 1;
+   : ^^^
+   `----
+
   x Expected a semicolon
    ,-[$DIR/tests/typescript-errors/issue-1391/case2/input.ts:2:5]
  2 | let b = 1;

diff --git a/crates/swc_ecma_parser/tests/typescript-errors/let/index.ts b/crates/swc_ecma_parser/tests/typescript-errors/let/index.ts
@@ -0,0 +1,3 @@
+export {};
+
+let let;
diff --git a/crates/swc_ecma_parser/tests/typescript-errors/let/index.ts.stderr b/crates/swc_ecma_parser/tests/typescript-errors/let/index.ts.stderr
@@ -0,0 +1,6 @@
+
+  x 'implements', 'interface', 'let', 'package', 'private', 'protected',  'public', 'static', or 'yield' cannot be used as an identifier in strict mode
+   ,-[$DIR/tests/typescript-errors/let/index.ts:3:1]
+ 3 | let let;
+   :     ^^^
+   `----
Benchmark suite	Current: `9a8fc27`	Previous: `dd862ba`	Ratio
`base_tr_fixer`	`27156` ns/iter (`± 4098`)	`23458` ns/iter (`± 358`)	`1.16`
`base_tr_resolver_and_hygiene`	`116596` ns/iter (`± 27451`)	`94958` ns/iter (`± 11217`)	`1.23`
`codegen_es2015`	`32087` ns/iter (`± 6215`)	`31110` ns/iter (`± 202`)	`1.03`
`codegen_es2016`	`33958` ns/iter (`± 7548`)	`31112` ns/iter (`± 171`)	`1.09`
`codegen_es2017`	`37246` ns/iter (`± 9011`)	`31195` ns/iter (`± 293`)	`1.19`
`codegen_es2018`	`34451` ns/iter (`± 5922`)	`31204` ns/iter (`± 167`)	`1.10`
`codegen_es2019`	`32134` ns/iter (`± 6189`)	`31125` ns/iter (`± 271`)	`1.03`
`codegen_es2020`	`31293` ns/iter (`± 9845`)	`31161` ns/iter (`± 261`)	`1.00`
`codegen_es3`	`31668` ns/iter (`± 5028`)	`31070` ns/iter (`± 209`)	`1.02`
`codegen_es5`	`38180` ns/iter (`± 3033`)	`31058` ns/iter (`± 189`)	`1.23`
`full_es2015`	`150752360` ns/iter (`± 23205927`)	`138677368` ns/iter (`± 14983760`)	`1.09`
`full_es2016`	`155223019` ns/iter (`± 27711548`)	`138060287` ns/iter (`± 5118241`)	`1.12`
`full_es2017`	`156784097` ns/iter (`± 17075356`)	`136987943` ns/iter (`± 5315834`)	`1.14`
`full_es2018`	`147493827` ns/iter (`± 22822412`)	`136026640` ns/iter (`± 4099888`)	`1.08`
`full_es2019`	`148090788` ns/iter (`± 22217304`)	`135483998` ns/iter (`± 3826059`)	`1.09`
`full_es2020`	`137405197` ns/iter (`± 23720264`)	`120466886` ns/iter (`± 9057124`)	`1.14`
`full_es3`	`193768115` ns/iter (`± 30713141`)	`183538594` ns/iter (`± 6100020`)	`1.06`
`full_es5`	`185024601` ns/iter (`± 39701090`)	`172977956` ns/iter (`± 5774500`)	`1.07`
`parser`	`606358` ns/iter (`± 69767`)	`563160` ns/iter (`± 12624`)	`1.08`
`ser_ast_node`	`138` ns/iter (`± 41`)	`146` ns/iter (`± 2`)	`0.95`
`ser_serde`	`151` ns/iter (`± 30`)	`145` ns/iter (`± 1`)	`1.04`
`emit_colors`	`9232158` ns/iter (`± 6033967`)	`15196037` ns/iter (`± 12186913`)	`0.61`
`emit_large`	`44440889` ns/iter (`± 68677058`)	`74537578` ns/iter (`± 99760353`)	`0.60`
`base_clone`	`2265152` ns/iter (`± 268938`)	`2388054` ns/iter (`± 180136`)	`0.95`
`fold_span`	`3981550` ns/iter (`± 817315`)	`3963974` ns/iter (`± 299223`)	`1.00`
`fold_span_panic`	`4187836` ns/iter (`± 571134`)	`4314857` ns/iter (`± 555378`)	`0.97`
`visit_mut_span`	`2769772` ns/iter (`± 448994`)	`3095537` ns/iter (`± 367251`)	`0.89`
`visit_mut_span_panic`	`2730047` ns/iter (`± 310318`)	`2913561` ns/iter (`± 250347`)	`0.94`
`usage_builtin_type`	`15537387` ns/iter (`± 10594049`)	`15855368` ns/iter (`± 9854246`)	`0.98`
`usage_property`	`429470` ns/iter (`± 143715`)	`395932` ns/iter (`± 4017`)	`1.08`
`boxing_boxed`	`118` ns/iter (`± 81`)	`134` ns/iter (`± 1`)	`0.88`
`boxing_boxed_clone`	`73` ns/iter (`± 24`)	`71` ns/iter (`± 0`)	`1.03`
`boxing_unboxed`	`128` ns/iter (`± 30`)	`120` ns/iter (`± 0`)	`1.07`
`boxing_unboxed_clone`	`59` ns/iter (`± 15`)	`63` ns/iter (`± 0`)	`0.94`
`time_10`	`300` ns/iter (`± 42`)	`305` ns/iter (`± 3`)	`0.98`
`time_15`	`669` ns/iter (`± 181`)	`718` ns/iter (`± 3`)	`0.93`
`time_20`	`1169` ns/iter (`± 174`)	`1364` ns/iter (`± 5`)	`0.86`
`time_40`	`4798` ns/iter (`± 1022`)	`7097` ns/iter (`± 32`)	`0.68`
`time_5`	`92` ns/iter (`± 11`)	`99` ns/iter (`± 0`)	`0.93`
`time_60`	`8437` ns/iter (`± 2515`)	`16110` ns/iter (`± 83`)	`0.52`
`es2015`	`11002898` ns/iter (`± 915357`)
`total`	`0` ns/iter (`± 0`)	`0` ns/iter (`± 0`)	`NaN`