Fix #437: only prohibit 'export type from "module" ' when flow is enabled

src/parser/statement.js

@@ -896,9 +896,7 @@ export default class StatementParser extends ExpressionParser {
 
   isExportDefaultSpecifier(): boolean {
     if (this.match(tt.name)) {
-      return this.state.value !== "type"
-          && this.state.value !== "async"
-          && this.state.value !== "interface";
+      return this.state.value !== "async";
     }
 
     if (!this.match(tt._default)) {

src/plugins/flow.js

@@ -1061,6 +1061,17 @@ export default (superClass: Class<Parser>): Class<Parser> => class extends super
         || super.shouldParseExportDeclaration();
   }
 
+  isExportDefaultSpecifier(): boolean {
+    if (
+      this.match(tt.name) &&
+      (this.state.value === "type" || this.state.value === "interface")
+    ) {
+      return false;
+    }
+
+    return super.isExportDefaultSpecifier();
+  }
+
   parseConditional(expr: N.Expression, noIn: ?boolean, startPos: number, startLoc: Position, refNeedsArrowPos?: Pos): N.Expression {
     // only do the expensive clone if there is a question mark
     // and if we come from inside parens

test/fixtures/experimental/export-extensions/default-type-with-flow/actual.js

@@ -0,0 +1 @@
+export type from 'test';

test/fixtures/experimental/export-extensions/default-type-with-flow/options.json

@@ -0,0 +1,5 @@
+{
+  "plugins": ["exportExtensions", "flow"],
+  "sourceType": "module",
+  "throws": "Unexpected token, expected = (1:17)"
+}

test/fixtures/experimental/export-extensions/default-type-without-flow/actual.js

@@ -0,0 +1 @@
+export type from 'test';

test/fixtures/experimental/export-extensions/default-type-without-flow/expected.json

@@ -0,0 +1,103 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 24,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 24
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 24,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 24
+      }
+    },
+    "sourceType": "module",
+    "body": [
+      {
+        "type": "ExportNamedDeclaration",
+        "start": 0,
+        "end": 24,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 24
+          }
+        },
+        "specifiers": [
+          {
+            "type": "ExportDefaultSpecifier",
+            "start": 7,
+            "end": 11,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 7
+              },
+              "end": {
+                "line": 1,
+                "column": 11
+              }
+            },
+            "exported": {
+              "type": "Identifier",
+              "start": 7,
+              "end": 11,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 7
+                },
+                "end": {
+                  "line": 1,
+                  "column": 11
+                },
+                "identifierName": "type"
+              },
+              "name": "type"
+            }
+          }
+        ],
+        "source": {
+          "type": "StringLiteral",
+          "start": 17,
+          "end": 23,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 17
+            },
+            "end": {
+              "line": 1,
+              "column": 23
+            }
+          },
+          "extra": {
+            "rawValue": "test",
+            "raw": "'test'"
+          },
+          "value": "test"
+        }
+      }
+    ],
+    "directives": []
+  }
+}