Fix parsing in non-declaration places

packages/babel-parser/src/parser/statement.js

@@ -76,7 +76,7 @@ export default class StatementParser extends ExpressionParser {
     return this.finishNode(node, "InterpreterDirective");
   }
 
-  isLet() {
+  isLet(declaration?: boolean): boolean {
     if (!this.isContextual("let")) {
       return false;
     }
@@ -93,6 +93,12 @@ export default class StatementParser extends ExpressionParser {
       return true;
     }
     if (isIdentifierStart(nextCh)) {
+      if (
+        !declaration &&
+        lineBreak.test(this.state.input.slice(this.state.end, next))
+      ) {
+        return false;
+      }
       let pos = next + 1;
       while (isIdentifierChar(this.state.input.charCodeAt(pos))) {
         ++pos;
@@ -122,7 +128,7 @@ export default class StatementParser extends ExpressionParser {
     const node = this.startNode();
     let kind;
 
-    if (this.isLet()) {
+    if (this.isLet(declaration)) {
       starttype = tt._var;
       kind = "let";
     }

packages/babel-parser/test/fixtures/es2015/let/let-as-identifier-6/input.js

@@ -0,0 +1,2 @@
+while (0) let
+foo

packages/babel-parser/test/fixtures/es2015/let/let-as-identifier-6/output.json

@@ -0,0 +1,134 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 17,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 2,
+      "column": 3
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 17,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 2,
+        "column": 3
+      }
+    },
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "WhileStatement",
+        "start": 0,
+        "end": 13,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 13
+          }
+        },
+        "test": {
+          "type": "NumericLiteral",
+          "start": 7,
+          "end": 8,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 7
+            },
+            "end": {
+              "line": 1,
+              "column": 8
+            }
+          },
+          "extra": {
+            "rawValue": 0,
+            "raw": "0"
+          },
+          "value": 0
+        },
+        "body": {
+          "type": "ExpressionStatement",
+          "start": 10,
+          "end": 13,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 10
+            },
+            "end": {
+              "line": 1,
+              "column": 13
+            }
+          },
+          "expression": {
+            "type": "Identifier",
+            "start": 10,
+            "end": 13,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 10
+              },
+              "end": {
+                "line": 1,
+                "column": 13
+              },
+              "identifierName": "let"
+            },
+            "name": "let"
+          }
+        }
+      },
+      {
+        "type": "ExpressionStatement",
+        "start": 14,
+        "end": 17,
+        "loc": {
+          "start": {
+            "line": 2,
+            "column": 0
+          },
+          "end": {
+            "line": 2,
+            "column": 3
+          }
+        },
+        "expression": {
+          "type": "Identifier",
+          "start": 14,
+          "end": 17,
+          "loc": {
+            "start": {
+              "line": 2,
+              "column": 0
+            },
+            "end": {
+              "line": 2,
+              "column": 3
+            },
+            "identifierName": "foo"
+          },
+          "name": "foo"
+        }
+      }
+    ],
+    "directives": []
+  }
+}

packages/babel-parser/test/fixtures/es2015/let/let-as-identifier-7/input.js

@@ -0,0 +1,2 @@
+while (0) let
+instanceof Foo

packages/babel-parser/test/fixtures/es2015/let/let-as-identifier-7/output.json

@@ -0,0 +1,135 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 28,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 2,
+      "column": 14
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 28,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 2,
+        "column": 14
+      }
+    },
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "WhileStatement",
+        "start": 0,
+        "end": 28,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 2,
+            "column": 14
+          }
+        },
+        "test": {
+          "type": "NumericLiteral",
+          "start": 7,
+          "end": 8,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 7
+            },
+            "end": {
+              "line": 1,
+              "column": 8
+            }
+          },
+          "extra": {
+            "rawValue": 0,
+            "raw": "0"
+          },
+          "value": 0
+        },
+        "body": {
+          "type": "ExpressionStatement",
+          "start": 10,
+          "end": 28,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 10
+            },
+            "end": {
+              "line": 2,
+              "column": 14
+            }
+          },
+          "expression": {
+            "type": "BinaryExpression",
+            "start": 10,
+            "end": 28,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 10
+              },
+              "end": {
+                "line": 2,
+                "column": 14
+              }
+            },
+            "left": {
+              "type": "Identifier",
+              "start": 10,
+              "end": 13,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 10
+                },
+                "end": {
+                  "line": 1,
+                  "column": 13
+                },
+                "identifierName": "let"
+              },
+              "name": "let"
+            },
+            "operator": "instanceof",
+            "right": {
+              "type": "Identifier",
+              "start": 25,
+              "end": 28,
+              "loc": {
+                "start": {
+                  "line": 2,
+                  "column": 11
+                },
+                "end": {
+                  "line": 2,
+                  "column": 14
+                },
+                "identifierName": "Foo"
+              },
+              "name": "Foo"
+            }
+          }
+        }
+      }
+    ],
+    "directives": []
+  }
+}

scripts/tests/test262/test262_whitelist.txt

@@ -1138,7 +1138,6 @@ language/statements/class/syntax/early-errors/class-definition-evaluation-block-
 language/statements/class/syntax/early-errors/class-definition-evaluation-scriptbody-duplicate-binding.js(default)
 language/statements/class/syntax/early-errors/class-definition-evaluation-scriptbody-duplicate-binding.js(strict mode)
 language/statements/const/redeclaration-error-from-within-strict-mode-function-const.js(default)
-language/statements/for-await-of/let-identifier-with-newline.js(default)
 language/statements/for-in/dstr/array-rest-before-elision.js(default)
 language/statements/for-in/dstr/array-rest-before-elision.js(strict mode)
 language/statements/for-in/dstr/array-rest-elision-invalid.js(default)
@@ -1151,7 +1150,6 @@ language/statements/for-in/head-let-bound-names-dup.js(default)
 language/statements/for-in/head-let-bound-names-dup.js(strict mode)
 language/statements/for-in/head-let-bound-names-in-stmt.js(default)
 language/statements/for-in/head-let-bound-names-in-stmt.js(strict mode)
-language/statements/for-in/let-identifier-with-newline.js(default)
 language/statements/for-of/dstr/array-rest-before-elision.js(default)
 language/statements/for-of/dstr/array-rest-before-elision.js(strict mode)
 language/statements/for-of/dstr/array-rest-elision-invalid.js(default)
@@ -1171,13 +1169,10 @@ language/statements/for-of/head-let-bound-names-in-stmt.js(default)
 language/statements/for-of/head-let-bound-names-in-stmt.js(strict mode)
 language/statements/for-of/head-var-no-expr.js(default)
 language/statements/for-of/head-var-no-expr.js(strict mode)
-language/statements/for-of/let-identifier-with-newline.js(default)
 language/statements/for/head-let-bound-names-in-stmt.js(default)
 language/statements/for/head-let-bound-names-in-stmt.js(strict mode)
-language/statements/for/let-identifier-with-newline.js(default)
 language/statements/function/dflt-params-duplicates.js(default)
 language/statements/generators/dflt-params-duplicates.js(default)
-language/statements/if/let-identifier-with-newline.js(default)
 language/statements/labeled/let-identifier-with-newline.js(default)
 language/statements/labeled/value-yield-non-strict-escaped.js(default)
 language/statements/labeled/value-yield-non-strict.js(default)
@@ -1312,6 +1307,4 @@ language/statements/try/early-catch-function.js(strict mode)
 language/statements/try/early-catch-lex.js(default)
 language/statements/try/early-catch-lex.js(strict mode)
 language/statements/try/early-catch-var.js(default)
-language/statements/try/early-catch-var.js(strict mode)
+language/statements/try/early-catch-var.js(strict mode)
-language/statements/while/let-identifier-with-newline.js(default)
-language/statements/with/let-identifier-with-newline.js(default)