Add estree parsing support for export * as A (#11254)

eslint/babel-eslint-parser/test/index.js

@@ -9,28 +9,38 @@ const BABEL_OPTIONS = {
     "@babel/eslint-shared-fixtures/config/babel.config.js",
   ),
 };
-const ALLOWED_PROPERTIES = [
+const PROPS_TO_REMOVE = [
   "importKind",
   "exportKind",
   "variance",
   "typeArguments",
 ];
+// We can remove needing to drop "exported" if null once this lands:
+// https://github.com/acornjs/acorn/pull/889
+const PROPS_TO_REMOVE_IF_NULL = ["exported"];
 
-function deeplyRemoveProperties(obj, props) {
+function deeplyRemoveProperties(obj, props, propsIfNull) {
   for (const [k, v] of Object.entries(obj)) {
     if (typeof v === "object") {
       if (Array.isArray(v)) {
         for (const el of v) {
-          if (el != null) deeplyRemoveProperties(el, props);
+          if (el != null) {
+            deeplyRemoveProperties(el, props, propsIfNull);
+          }
         }
       }
 
-      if (props.includes(k)) delete obj[k];
-      else if (v != null) deeplyRemoveProperties(v, props);
+      if (props.includes(k) || (propsIfNull.includes(k) && v === null)) {
+        delete obj[k];
+      } else if (v != null) {
+        deeplyRemoveProperties(v, props, propsIfNull);
+      }
       continue;
     }
 
-    if (props.includes(k)) delete obj[k];
+    if (props.includes(k) || (propsIfNull.includes(k) && v === null)) {
+      delete obj[k];
+    }
   }
 }
 
@@ -62,7 +72,7 @@ describe("Babel and Espree", () => {
       eslintScopeManager: true,
       babelOptions: BABEL_OPTIONS,
     }).ast;
-    deeplyRemoveProperties(babelAST, ALLOWED_PROPERTIES);
+    deeplyRemoveProperties(babelAST, PROPS_TO_REMOVE, PROPS_TO_REMOVE_IF_NULL);
     expect(babelAST).toEqual(espreeAST);
   }
 
@@ -266,6 +276,17 @@ describe("Babel and Espree", () => {
     parseAndAssertSame('export * from "foo";');
   });
 
+  // Espree doesn't support `export * as ns` yet
+  it("export * as ns", () => {
+    const code = 'export * as Foo from "foo";';
+    const babylonAST = parseForESLint(code, {
+      eslintVisitorKeys: true,
+      eslintScopeManager: true,
+      babelOptions: BABEL_OPTIONS,
+    }).ast;
+    expect(babylonAST.tokens[1].type).toEqual("Punctuator");
+  });
+
   it("export named", () => {
     parseAndAssertSame("var foo = 1;export { foo };");
   });

packages/babel-parser/src/plugins/estree.js

@@ -407,4 +407,28 @@ export default (superClass: Class<Parser>): Class<Parser> =>
 
       super.toReferencedListDeep(exprList, isParenthesizedExpr);
     }
+
+    parseExport(node: N.Node) {
+      super.parseExport(node);
+
+      switch (node.type) {
+        case "ExportAllDeclaration":
+          node.exported = null;
+          break;
+
+        case "ExportNamedDeclaration":
+          if (
+            node.specifiers.length === 1 &&
+            node.specifiers[0].type === "ExportNamespaceSpecifier"
+          ) {
+            node.type = "ExportAllDeclaration";
+            node.exported = node.specifiers[0].exported;
+            delete node.specifiers;
+          }
+
+          break;
+      }
+
+      return node;
+    }
   };

packages/babel-parser/test/fixtures/estree/export/batch/input.js

@@ -0,0 +1 @@
+export * from "foo";

packages/babel-parser/test/fixtures/estree/export/batch/output.json

@@ -0,0 +1,67 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 20,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 20
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 20,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 20
+      }
+    },
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExportAllDeclaration",
+        "start": 0,
+        "end": 20,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 20
+          }
+        },
+        "source": {
+          "type": "Literal",
+          "start": 14,
+          "end": 19,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 14
+            },
+            "end": {
+              "line": 1,
+              "column": 19
+            }
+          },
+          "value": "foo",
+          "raw": "\"foo\""
+        },
+        "exported": null
+      }
+    ]
+  }
+}

packages/babel-parser/test/fixtures/estree/export/ns-from/input.js

@@ -0,0 +1 @@
+export * as A from 'test';

packages/babel-parser/test/fixtures/estree/export/ns-from/output.json

@@ -0,0 +1,83 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 26,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 26
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 26,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 26
+      }
+    },
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "ExportAllDeclaration",
+        "start": 0,
+        "end": 26,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 26
+          }
+        },
+        "source": {
+          "type": "Literal",
+          "start": 19,
+          "end": 25,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 19
+            },
+            "end": {
+              "line": 1,
+              "column": 25
+            }
+          },
+          "value": "test",
+          "raw": "'test'"
+        },
+        "exported": {
+          "type": "Identifier",
+          "start": 12,
+          "end": 13,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 12
+            },
+            "end": {
+              "line": 1,
+              "column": 13
+            },
+            "identifierName": "A"
+          },
+          "name": "A"
+        }
+      }
+    ]
+  }
+}

packages/babel-parser/test/fixtures/estree/export/options.json

@@ -0,0 +1,4 @@
+{
+  "plugins": ["estree"],
+  "sourceType": "module"
+}