Fix handling of comments with decorators before export

babel · Oct 10, 2022 · 792f629 · 792f629
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commit 792f629
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Showing 19 changed files with 609 additions and 7 deletions.
diff --git a/packages/babel-generator/test/fixtures/comments/decorators-after-export/input.js b/packages/babel-generator/test/fixtures/comments/decorators-after-export/input.js
@@ -0,0 +1,2 @@
+/* 1 */ export /* 2 */ @dec1 /* 3 */ @dec2
+/* 4 */ class /* 5 */ C /* 6 */ { /* 7 */ } /* 8 */
diff --git a/packages/babel-generator/test/fixtures/comments/decorators-after-export/options.json b/packages/babel-generator/test/fixtures/comments/decorators-after-export/options.json
@@ -0,0 +1,4 @@
+{
+  "plugins": [["decorators", { "decoratorsBeforeExport": false }]],
+  "decoratorsBeforeExport": false
+}
diff --git a/packages/babel-generator/test/fixtures/comments/decorators-after-export/output.js b/packages/babel-generator/test/fixtures/comments/decorators-after-export/output.js
@@ -0,0 +1,3 @@
+/* 1 */export /* 2 */@dec1
+/* 3 */@dec2
+/* 4 */class /* 5 */C /* 6 */ {/* 7 */} /* 8 */
diff --git a/packages/babel-generator/test/fixtures/comments/decorators-before-export/input.js b/packages/babel-generator/test/fixtures/comments/decorators-before-export/input.js
@@ -0,0 +1,2 @@
+/* 1 */ @dec1 /* 2 */ @dec2 /* 3 */
+export /* 4 */ class /* 5 */ C /* 6 */ { /* 7 */ } /* 8 */
diff --git a/packages/babel-generator/test/fixtures/comments/decorators-before-export/options.json b/packages/babel-generator/test/fixtures/comments/decorators-before-export/options.json
@@ -0,0 +1,4 @@
+{
+  "plugins": [["decorators", { "decoratorsBeforeExport": true }]],
+  "decoratorsBeforeExport": true
+}
diff --git a/packages/babel-generator/test/fixtures/comments/decorators-before-export/output.js b/packages/babel-generator/test/fixtures/comments/decorators-before-export/output.js
@@ -0,0 +1,3 @@
+/* 1 */@dec1
+/* 2 */@dec2
+/* 3 */export /* 4 */class /* 5 */C /* 6 */ {/* 7 */} /* 8 */
diff --git a/packages/babel-generator/test/fixtures/comments/decorators-legacy-before-export/input.js b/packages/babel-generator/test/fixtures/comments/decorators-legacy-before-export/input.js
@@ -0,0 +1,2 @@
+/* 1 */ @dec1 /* 2 */ @dec2 /* 3 */
+export /* 4 */ class /* 5 */ C /* 6 */ { /* 7 */ } /* 8 */
diff --git a/packages/babel-generator/test/fixtures/comments/decorators-legacy-before-export/options.json b/packages/babel-generator/test/fixtures/comments/decorators-legacy-before-export/options.json
@@ -0,0 +1,4 @@
+{
+  "plugins": ["decorators-legacy"],
+  "decoratorsBeforeExport": true
+}
diff --git a/packages/babel-generator/test/fixtures/comments/decorators-legacy-before-export/output.js b/packages/babel-generator/test/fixtures/comments/decorators-legacy-before-export/output.js
@@ -0,0 +1,3 @@
+/* 1 */@dec1
+/* 2 */@dec2
+/* 3 */export /* 4 */class /* 5 */C /* 6 */ {/* 7 */} /* 8 */
diff --git a/packages/babel-parser/src/parser/statement.ts b/packages/babel-parser/src/parser/statement.ts
@@ -522,13 +522,49 @@ export default abstract class StatementParser extends ExpressionParser {
     }
   }
 
+  decoratorsEnabledBeforeExport(): boolean {
+    if (this.hasPlugin("decorators-legacy")) return true;
+    return (
+      this.hasPlugin("decorators") &&
+      !!this.getPluginOption("decorators", "decoratorsBeforeExport")
+    );
+  }
+
   takeDecorators(node: N.HasDecorators): void {
     const decorators =
       this.state.decoratorStack[this.state.decoratorStack.length - 1];
     if (decorators.length) {
       node.decorators = decorators;
       this.resetStartLocationFromNode(node, decorators[0]);
       this.state.decoratorStack[this.state.decoratorStack.length - 1] = [];
+
+      // In case of decorators followed by `export`, we manually mark the
+      // comments between `export` and `class` as leading comments of the
+      // class declaration node.
+      // This is needed because the class location range overlaps with
+      // `export`, and thus they would me marked as inner comments of
+      // the class declaration.
+      //   @dec export /* comment */ class Foo {}
+      // See [parseDecorators] for the hanling of comments before decorators
+      if (this.decoratorsEnabledBeforeExport()) {
+        const {
+          start,
+          lastTokStart,
+          lastTokEndLoc: { index: lastTokEnd },
+        } = this.state;
+
+        if (this.input.slice(lastTokStart, lastTokEnd) === "export") {
+          const { commentStack } = this.state;
+          for (let i = commentStack.length - 1; i >= 0; i--) {
+            const commentWS = commentStack[i];
+            if (commentWS.start >= lastTokEnd && commentWS.end <= start) {
+              commentWS.trailingNode = node as N.Node;
+            } else if (commentWS.end < lastTokEnd) {
+              break;
+            }
+          }
+        }
+      }
     }
   }
 
@@ -537,8 +573,9 @@ export default abstract class StatementParser extends ExpressionParser {
   }
 
   parseDecorators(this: Parser, allowExport?: boolean): void {
-    const currentContextDecorators =
-      this.state.decoratorStack[this.state.decoratorStack.length - 1];
+    const { decoratorStack } = this.state;
+    const currentContextDecorators = decoratorStack[decoratorStack.length - 1];
+
     while (this.match(tt.at)) {
       const decorator = this.parseDecorator();
       currentContextDecorators.push(decorator);
@@ -549,12 +586,27 @@ export default abstract class StatementParser extends ExpressionParser {
         this.unexpected();
       }
 
-      if (
-        this.hasPlugin("decorators") &&
-        !this.getPluginOption("decorators", "decoratorsBeforeExport")
-      ) {
+      if (!this.decoratorsEnabledBeforeExport()) {
         this.raise(Errors.DecoratorExportClass, { at: this.state.startLoc });
       }
+
+      // In case of comments followed by a decorator followed by `export`,
+      // we manually attach them to the decorator node rather than to the
+      // class declaration node. This is because the class location range
+      // overlaps with `export`, and this causes confusing comments behavior:
+      //   /* comment */ @dec export class Foo {}
+      // See [takeDecorators] for the hanling of comments after `export`
+      const firstDecorator = decoratorStack[decoratorStack.length - 1][0];
+      const { commentStack } = this.state;
+      for (let i = commentStack.length - 1; i >= 0; i--) {
+        const commentWS = commentStack[i];
+        if (commentWS.trailingNode === firstDecorator) {
+          this.finalizeComment(commentWS);
+          commentStack.splice(i, 1);
+        } else if (commentWS.end < firstDecorator.start) {
+          break;
+        }
+      }
     } else if (!this.canHaveLeadingDecorator()) {
       throw this.raise(Errors.UnexpectedLeadingDecorator, {
         at: this.state.startLoc,
@@ -1472,9 +1524,10 @@ export default abstract class StatementParser extends ExpressionParser {
     isStatement: /* T === ClassDeclaration */ boolean,
     optionalId?: boolean,
   ): T {
-    this.next();
     this.takeDecorators(node);
 
+    this.next(); // 'class'
+
     // A class definition is always strict mode code.
     const oldStrict = this.state.strict;
     this.state.strict = true;

diff --git a/packages/babel-parser/test/fixtures/comments/decorators/decorators-after-export/input.js b/packages/babel-parser/test/fixtures/comments/decorators/decorators-after-export/input.js
@@ -0,0 +1,2 @@
+/* 1 */ export /* 2 */ @dec1 /* 3 */ @dec2
+/* 4 */ class /* 5 */ C /* 6 */ { /* 7 */ } /* 8 */
diff --git a/packages/babel-parser/test/fixtures/comments/decorators/decorators-after-export/options.json b/packages/babel-parser/test/fixtures/comments/decorators/decorators-after-export/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": [["decorators", { "decoratorsBeforeExport": false }]]
+}
diff --git a/packages/babel-parser/test/fixtures/comments/decorators/decorators-after-export/output.json b/packages/babel-parser/test/fixtures/comments/decorators/decorators-after-export/output.json
@@ -0,0 +1,169 @@
+{
+  "type": "File",
+  "start":0,"end":94,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":2,"column":51,"index":94}},
+  "errors": [
+    "SyntaxError: 'import' and 'export' may appear only with 'sourceType: \"module\"' (1:8)"
+  ],
+  "program": {
+    "type": "Program",
+    "start":0,"end":94,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":2,"column":51,"index":94}},
+    "sourceType": "script",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExportNamedDeclaration",
+        "start":8,"end":86,"loc":{"start":{"line":1,"column":8,"index":8},"end":{"line":2,"column":43,"index":86}},
+        "specifiers": [],
+        "source": null,
+        "declaration": {
+          "type": "ClassDeclaration",
+          "start":23,"end":86,"loc":{"start":{"line":1,"column":23,"index":23},"end":{"line":2,"column":43,"index":86}},
+          "decorators": [
+            {
+              "type": "Decorator",
+              "start":23,"end":28,"loc":{"start":{"line":1,"column":23,"index":23},"end":{"line":1,"column":28,"index":28}},
+              "expression": {
+                "type": "Identifier",
+                "start":24,"end":28,"loc":{"start":{"line":1,"column":24,"index":24},"end":{"line":1,"column":28,"index":28},"identifierName":"dec1"},
+                "name": "dec1"
+              },
+              "trailingComments": [
+                {
+                  "type": "CommentBlock",
+                  "value": " 3 ",
+                  "start":29,"end":36,"loc":{"start":{"line":1,"column":29,"index":29},"end":{"line":1,"column":36,"index":36}}
+                }
+              ]
+            },
+            {
+              "type": "Decorator",
+              "start":37,"end":42,"loc":{"start":{"line":1,"column":37,"index":37},"end":{"line":1,"column":42,"index":42}},
+              "expression": {
+                "type": "Identifier",
+                "start":38,"end":42,"loc":{"start":{"line":1,"column":38,"index":38},"end":{"line":1,"column":42,"index":42},"identifierName":"dec2"},
+                "name": "dec2"
+              },
+              "trailingComments": [
+                {
+                  "type": "CommentBlock",
+                  "value": " 4 ",
+                  "start":43,"end":50,"loc":{"start":{"line":2,"column":0,"index":43},"end":{"line":2,"column":7,"index":50}}
+                }
+              ],
+              "leadingComments": [
+                {
+                  "type": "CommentBlock",
+                  "value": " 3 ",
+                  "start":29,"end":36,"loc":{"start":{"line":1,"column":29,"index":29},"end":{"line":1,"column":36,"index":36}}
+                }
+              ]
+            }
+          ],
+          "id": {
+            "type": "Identifier",
+            "start":65,"end":66,"loc":{"start":{"line":2,"column":22,"index":65},"end":{"line":2,"column":23,"index":66},"identifierName":"C"},
+            "name": "C",
+            "trailingComments": [
+              {
+                "type": "CommentBlock",
+                "value": " 6 ",
+                "start":67,"end":74,"loc":{"start":{"line":2,"column":24,"index":67},"end":{"line":2,"column":31,"index":74}}
+              }
+            ],
+            "leadingComments": [
+              {
+                "type": "CommentBlock",
+                "value": " 5 ",
+                "start":57,"end":64,"loc":{"start":{"line":2,"column":14,"index":57},"end":{"line":2,"column":21,"index":64}}
+              }
+            ]
+          },
+          "superClass": null,
+          "body": {
+            "type": "ClassBody",
+            "start":75,"end":86,"loc":{"start":{"line":2,"column":32,"index":75},"end":{"line":2,"column":43,"index":86}},
+            "body": [],
+            "innerComments": [
+              {
+                "type": "CommentBlock",
+                "value": " 7 ",
+                "start":77,"end":84,"loc":{"start":{"line":2,"column":34,"index":77},"end":{"line":2,"column":41,"index":84}}
+              }
+            ],
+            "leadingComments": [
+              {
+                "type": "CommentBlock",
+                "value": " 6 ",
+                "start":67,"end":74,"loc":{"start":{"line":2,"column":24,"index":67},"end":{"line":2,"column":31,"index":74}}
+              }
+            ]
+          },
+          "leadingComments": [
+            {
+              "type": "CommentBlock",
+              "value": " 2 ",
+              "start":15,"end":22,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":22,"index":22}}
+            }
+          ]
+        },
+        "trailingComments": [
+          {
+            "type": "CommentBlock",
+            "value": " 8 ",
+            "start":87,"end":94,"loc":{"start":{"line":2,"column":44,"index":87},"end":{"line":2,"column":51,"index":94}}
+          }
+        ],
+        "leadingComments": [
+          {
+            "type": "CommentBlock",
+            "value": " 1 ",
+            "start":0,"end":7,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":7,"index":7}}
+          }
+        ]
+      }
+    ],
+    "directives": []
+  },
+  "comments": [
+    {
+      "type": "CommentBlock",
+      "value": " 1 ",
+      "start":0,"end":7,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":7,"index":7}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 2 ",
+      "start":15,"end":22,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":22,"index":22}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 3 ",
+      "start":29,"end":36,"loc":{"start":{"line":1,"column":29,"index":29},"end":{"line":1,"column":36,"index":36}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 4 ",
+      "start":43,"end":50,"loc":{"start":{"line":2,"column":0,"index":43},"end":{"line":2,"column":7,"index":50}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 5 ",
+      "start":57,"end":64,"loc":{"start":{"line":2,"column":14,"index":57},"end":{"line":2,"column":21,"index":64}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 6 ",
+      "start":67,"end":74,"loc":{"start":{"line":2,"column":24,"index":67},"end":{"line":2,"column":31,"index":74}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 7 ",
+      "start":77,"end":84,"loc":{"start":{"line":2,"column":34,"index":77},"end":{"line":2,"column":41,"index":84}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 8 ",
+      "start":87,"end":94,"loc":{"start":{"line":2,"column":44,"index":87},"end":{"line":2,"column":51,"index":94}}
+    }
+  ]
+}
diff --git a/packages/babel-parser/test/fixtures/comments/decorators/decorators-before-export/input.js b/packages/babel-parser/test/fixtures/comments/decorators/decorators-before-export/input.js
@@ -0,0 +1,2 @@
+/* 1 */ @dec1 /* 2 */ @dec2 /* 3 */
+export /* 4 */ class /* 5 */ C /* 6 */ { /* 7 */ } /* 8 */
diff --git a/...ages/babel-parser/test/fixtures/comments/decorators/decorators-before-export/options.json b/...ages/babel-parser/test/fixtures/comments/decorators/decorators-before-export/options.json
@@ -0,0 +1,3 @@
+{
+  "plugins": [["decorators", { "decoratorsBeforeExport": true }]]
+}