From 990675d28e67f92b680c7094b3ceeac9f3bf1ce4 Mon Sep 17 00:00:00 2001
From: Daniel Tschinder <daniel@tschinder.de>
Date: Fri, 19 May 2017 10:28:42 +0200
Subject: [PATCH] Fix #437: only prohibit 'export type from "module" ' when
 flow is enabled (#438) (#531)

* Only prohibit 'export type' when flow is enabled

* Fix lint
---
 src/parser/statement.js                       |   4 +-
 src/plugins/flow.js                           |  13 +++
 .../default-type-with-flow/actual.js          |   1 +
 .../default-type-with-flow/options.json       |   5 +
 .../default-type-without-flow/actual.js       |   1 +
 .../default-type-without-flow/expected.json   | 103 ++++++++++++++++++
 6 files changed, 124 insertions(+), 3 deletions(-)
 create mode 100644 test/fixtures/experimental/export-extensions/default-type-with-flow/actual.js
 create mode 100644 test/fixtures/experimental/export-extensions/default-type-with-flow/options.json
 create mode 100644 test/fixtures/experimental/export-extensions/default-type-without-flow/actual.js
 create mode 100644 test/fixtures/experimental/export-extensions/default-type-without-flow/expected.json

diff --git a/src/parser/statement.js b/src/parser/statement.js
index 488a554b94..d8d0eafb91 100644
--- a/src/parser/statement.js
+++ b/src/parser/statement.js
@@ -883,9 +883,7 @@ pp.parseExportDeclaration = function () {
 
 pp.isExportDefaultSpecifier = function () {
   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)) {
diff --git a/src/plugins/flow.js b/src/plugins/flow.js
index fe6aa0a2ff..78e2f846bb 100644
--- a/src/plugins/flow.js
+++ b/src/plugins/flow.js
@@ -930,6 +930,19 @@ export default function (instance) {
     };
   });
 
+  instance.extend("isExportDefaultSpecifier", function (inner) {
+    return function () {
+      if (
+        this.match(tt.name) &&
+        (this.state.value === "type" || this.state.value === "interface")
+      ) {
+        return false;
+      }
+
+      return inner.call(this);
+    };
+  });
+
   instance.extend("parseConditional", function (inner) {
     return function (expr, noIn, startPos, startLoc, refNeedsArrowPos) {
       // only do the expensive clone if there is a question mark
diff --git a/test/fixtures/experimental/export-extensions/default-type-with-flow/actual.js b/test/fixtures/experimental/export-extensions/default-type-with-flow/actual.js
new file mode 100644
index 0000000000..2086d067fc
--- /dev/null
+++ b/test/fixtures/experimental/export-extensions/default-type-with-flow/actual.js
@@ -0,0 +1 @@
+export type from 'test';
diff --git a/test/fixtures/experimental/export-extensions/default-type-with-flow/options.json b/test/fixtures/experimental/export-extensions/default-type-with-flow/options.json
new file mode 100644
index 0000000000..3d735abd0a
--- /dev/null
+++ b/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)"
+}
diff --git a/test/fixtures/experimental/export-extensions/default-type-without-flow/actual.js b/test/fixtures/experimental/export-extensions/default-type-without-flow/actual.js
new file mode 100644
index 0000000000..2086d067fc
--- /dev/null
+++ b/test/fixtures/experimental/export-extensions/default-type-without-flow/actual.js
@@ -0,0 +1 @@
+export type from 'test';
diff --git a/test/fixtures/experimental/export-extensions/default-type-without-flow/expected.json b/test/fixtures/experimental/export-extensions/default-type-without-flow/expected.json
new file mode 100644
index 0000000000..8b0ad961f6
--- /dev/null
+++ b/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": []
+  }
+}
\ No newline at end of file