New: ecmaFeatures.impliedStrict (fixes: eslint#227)

nre · Jan 3, 2016 · ce69b3a · ce69b3a
1 parent 73a079c
commit ce69b3a
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Showing 8 changed files with 497 additions and 5 deletions.
diff --git a/README.md b/README.md
@@ -60,6 +60,9 @@ var ast = espree.parse(code, {
         // enable return in global scope
         globalReturn: true,
 
+        // enable implied strict mode (if ecmaVersion >= 5)
+        impliedStrict: true,
+
         // allow experimental object rest/spread
         experimentalObjectRestSpread: true
     }

diff --git a/espree.js b/espree.js
@@ -266,6 +266,15 @@ pp.extend("checkLVal", function(checkLVal) {
     };
 });
 
+pp.extend("parseTopLevel", function(parseTopLevel) {
+    return /** @this acorn.Parser */ function(node) {
+        if (extra.ecmaFeatures.impliedStrict) {
+            this.strict = this.options.ecmaVersion >= 5;
+        }
+        return parseTopLevel.call(this, node);
+    };
+});
+
 /**
  * Method to parse an object rest or object spread.
  * @returns {ASTNode} The node representing object rest or object spread.
@@ -422,6 +431,7 @@ pp.extend("jsx_readString", function(jsxReadString) {
 function tokenize(code, options) {
     var toString,
         tokens,
+        impliedStrict,
         translator = new TokenTranslator(tt, code);
 
     toString = String;
@@ -478,6 +488,8 @@ function tokenize(code, options) {
     // apply parsing flags
     if (options.ecmaFeatures && typeof options.ecmaFeatures === "object") {
         extra.ecmaFeatures = options.ecmaFeatures;
+        impliedStrict = extra.ecmaFeatures.impliedStrict;
+        extra.ecmaFeatures.impliedStrict = typeof impliedStrict === "boolean" && impliedStrict;
     }
 
     try {
@@ -554,6 +566,7 @@ function parse(code, options) {
     var program,
         toString = String,
         translator,
+        impliedStrict,
         acornOptions = {
             ecmaVersion: 5
         };
@@ -620,6 +633,8 @@ function parse(code, options) {
         // apply parsing flags after sourceType to allow overriding
         if (options.ecmaFeatures && typeof options.ecmaFeatures === "object") {
             extra.ecmaFeatures = options.ecmaFeatures;
+            impliedStrict = extra.ecmaFeatures.impliedStrict;
+            extra.ecmaFeatures.impliedStrict = typeof impliedStrict === "boolean" && impliedStrict;
             if (options.ecmaFeatures.globalReturn) {
                 acornOptions.allowReturnOutsideFunction = true;
             }

diff --git a/lib/features.js b/lib/features.js
@@ -46,6 +46,9 @@ module.exports = {
     // allow return statement in global scope
     globalReturn: false,
 
+    // allow implied strict mode
+    impliedStrict: false,
+
     // allow experimental object rest/spread
     experimentalObjectRestSpread: false
 };
diff --git a/tests/fixtures/ecma-features/impliedStrict/global-strict-violation.result.js b/tests/fixtures/ecma-features/impliedStrict/global-strict-violation.result.js
@@ -0,0 +1,132 @@
+module.exports = {
+    "type": "Program",
+    "sourceType": "script",
+    "body": [
+        {
+            "type": "VariableDeclaration",
+            "declarations": [
+                {
+                    "type": "VariableDeclarator",
+                    "id": {
+                        "type": "Identifier",
+                        "name": "let",
+                        "range": [
+                            4,
+                            7
+                        ],
+                        "loc": {
+                            "start": {
+                                "line": 1,
+                                "column": 4
+                            },
+                            "end": {
+                                "line": 1,
+                                "column": 7
+                            }
+                        }
+                    },
+                    "init": null,
+                    "range": [
+                        4,
+                        7
+                    ],
+                    "loc": {
+                        "start": {
+                            "line": 1,
+                            "column": 4
+                        },
+                        "end": {
+                            "line": 1,
+                            "column": 7
+                        }
+                    }
+                }
+            ],
+            "kind": "var",
+            "range": [
+                0,
+                8
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 0
+                },
+                "end": {
+                    "line": 1,
+                    "column": 8
+                }
+            }
+        }
+    ],
+    "range": [
+        0,
+        8
+    ],
+    "loc": {
+        "start": {
+            "line": 1,
+            "column": 0
+        },
+        "end": {
+            "line": 1,
+            "column": 8
+        }
+    },
+    "tokens": [
+        {
+            "type": "Keyword",
+            "value": "var",
+            "range": [
+                0,
+                3
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 0
+                },
+                "end": {
+                    "line": 1,
+                    "column": 3
+                }
+            }
+        },
+        {
+            "type": "Identifier",
+            "value": "let",
+            "range": [
+                4,
+                7
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 4
+                },
+                "end": {
+                    "line": 1,
+                    "column": 7
+                }
+            }
+        },
+        {
+            "type": "Punctuator",
+            "value": ";",
+            "range": [
+                7,
+                8
+            ],
+            "loc": {
+                "start": {
+                    "line": 1,
+                    "column": 7
+                },
+                "end": {
+                    "line": 1,
+                    "column": 8
+                }
+            }
+        }
+    ]
+};
diff --git a/tests/fixtures/ecma-features/impliedStrict/global-strict-violation.src.js b/tests/fixtures/ecma-features/impliedStrict/global-strict-violation.src.js
@@ -0,0 +1 @@
+var let;