Fix comments attachment

babel · May 17, 2023 · 15a4308 · 15a4308
1 parent 893442d
commit 15a4308
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diff --git a/packages/babel-parser/src/parser/comments.ts b/packages/babel-parser/src/parser/comments.ts
@@ -246,6 +246,40 @@ export default class CommentsParser extends BaseParser {
     }
   }
 
+  /* eslint-disable no-irregular-whitespace */
+  /**
+   * Reset previous node leading comments. Used in import phase modifiers
+   * parsing. We parse `module` in `import module foo from ...` as an
+   * identifier but may reinterpret it into a phase modifier later. In this
+   * case the identifier is not part of the AST and we should sync the
+   * knowledge to commentStacks
+   *
+   * For example, when parsing
+   * ```
+   * import /* 1 */ module a from "a";
+   * ```
+   * the comment whitespace `/* 1 */` has trailing node Identifier(module). When
+   * we see that `module` is not a default import binding, we mark `/* 1 */` as
+   * inner comments of the ImportDeclaration. So `/* 1 */` should be detached from
+   * the Identifier node.
+   *
+   * @param node the last finished AST node _before_ current token
+   */
+  /* eslint-enable no-irregular-whitespace */
+  resetPreviousNodeLeadingComments(node: Node) {
+    const { commentStack } = this.state;
+    const { length } = commentStack;
+    if (length === 0) return;
+
+    for (let i = length - 1; i >= 0; i--) {
+      const commentWS = commentStack[i];
+      if (commentWS.trailingNode === node) {
+        commentWS.trailingNode = null;
+      }
+      if (commentWS.end < node.start) break;
+    }
+  }
+
   /**
    * Attach a node to the comment whitespaces right before/after
    * the given range.

diff --git a/packages/babel-parser/src/parser/statement.ts b/packages/babel-parser/src/parser/statement.ts
@@ -2958,6 +2958,7 @@ export default abstract class StatementParser extends ExpressionParser {
         type !== tt.comma;
 
     if (isImportPhase) {
+      this.resetPreviousNodeLeadingComments(phaseIdentifier);
       this.applyImportPhase(
         node as Undone<N.ImportDeclaration>,
         isExport,

diff --git a/packages/babel-parser/test/fixtures/experimental/import-reflection/comments/input.mjs b/packages/babel-parser/test/fixtures/experimental/import-reflection/comments/input.mjs
@@ -0,0 +1 @@
+/* 0 */ import /* 1 */ module /* 2 */ Foo /* 3 */ from /* 4 */ "foo" /* 5 */;
diff --git a/packages/babel-parser/test/fixtures/experimental/import-reflection/comments/output.json b/packages/babel-parser/test/fixtures/experimental/import-reflection/comments/output.json
@@ -0,0 +1,112 @@
+{
+  "type": "File",
+  "start":0,"end":77,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":77,"index":77}},
+  "program": {
+    "type": "Program",
+    "start":0,"end":77,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":77,"index":77}},
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ImportDeclaration",
+        "start":8,"end":77,"loc":{"start":{"line":1,"column":8,"index":8},"end":{"line":1,"column":77,"index":77}},
+        "module": true,
+        "specifiers": [
+          {
+            "type": "ImportDefaultSpecifier",
+            "start":38,"end":41,"loc":{"start":{"line":1,"column":38,"index":38},"end":{"line":1,"column":41,"index":41}},
+            "local": {
+              "type": "Identifier",
+              "start":38,"end":41,"loc":{"start":{"line":1,"column":38,"index":38},"end":{"line":1,"column":41,"index":41},"identifierName":"Foo"},
+              "name": "Foo"
+            },
+            "trailingComments": [
+              {
+                "type": "CommentBlock",
+                "value": " 3 ",
+                "start":42,"end":49,"loc":{"start":{"line":1,"column":42,"index":42},"end":{"line":1,"column":49,"index":49}}
+              }
+            ],
+            "leadingComments": [
+              {
+                "type": "CommentBlock",
+                "value": " 2 ",
+                "start":30,"end":37,"loc":{"start":{"line":1,"column":30,"index":30},"end":{"line":1,"column":37,"index":37}}
+              }
+            ]
+          }
+        ],
+        "source": {
+          "type": "StringLiteral",
+          "start":63,"end":68,"loc":{"start":{"line":1,"column":63,"index":63},"end":{"line":1,"column":68,"index":68}},
+          "extra": {
+            "rawValue": "foo",
+            "raw": "\"foo\""
+          },
+          "value": "foo",
+          "trailingComments": [
+            {
+              "type": "CommentBlock",
+              "value": " 5 ",
+              "start":69,"end":76,"loc":{"start":{"line":1,"column":69,"index":69},"end":{"line":1,"column":76,"index":76}}
+            }
+          ],
+          "leadingComments": [
+            {
+              "type": "CommentBlock",
+              "value": " 4 ",
+              "start":55,"end":62,"loc":{"start":{"line":1,"column":55,"index":55},"end":{"line":1,"column":62,"index":62}}
+            }
+          ]
+        },
+        "innerComments": [
+          {
+            "type": "CommentBlock",
+            "value": " 1 ",
+            "start":15,"end":22,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":22,"index":22}}
+          }
+        ],
+        "leadingComments": [
+          {
+            "type": "CommentBlock",
+            "value": " 0 ",
+            "start":0,"end":7,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":7,"index":7}}
+          }
+        ]
+      }
+    ],
+    "directives": []
+  },
+  "comments": [
+    {
+      "type": "CommentBlock",
+      "value": " 0 ",
+      "start":0,"end":7,"loc":{"start":{"line":1,"column":0,"index":0},"end":{"line":1,"column":7,"index":7}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 1 ",
+      "start":15,"end":22,"loc":{"start":{"line":1,"column":15,"index":15},"end":{"line":1,"column":22,"index":22}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 2 ",
+      "start":30,"end":37,"loc":{"start":{"line":1,"column":30,"index":30},"end":{"line":1,"column":37,"index":37}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 3 ",
+      "start":42,"end":49,"loc":{"start":{"line":1,"column":42,"index":42},"end":{"line":1,"column":49,"index":49}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 4 ",
+      "start":55,"end":62,"loc":{"start":{"line":1,"column":55,"index":55},"end":{"line":1,"column":62,"index":62}}
+    },
+    {
+      "type": "CommentBlock",
+      "value": " 5 ",
+      "start":69,"end":76,"loc":{"start":{"line":1,"column":69,"index":69},"end":{"line":1,"column":76,"index":76}}
+    }
+  ]
+}