Flow: interface identifier should be declared in the scope

packages/babel-generator/test/fixtures/flow/declare-statements/input.js

@@ -11,13 +11,13 @@ declare class A { static [ indexer: number]: string }
 declare class A { static () : number }
 declare class B { (): number }
 declare class A mixins B<T>, C {}
-declare type A = string
+declare type A1 = string
 declare type T<U> = { [k:string]: U }
-declare type B = {
+declare type B1 = {
   fn?: (foo: string) => void,
 }
-declare interface I { foo: string }
-declare interface I<T> { foo: T }
+declare interface I1 { foo: string }
+declare interface I2<T> { foo: T }
 declare module.exports: { foo: string }
 declare opaque type Foo<T>: Bar<T>;
 declare opaque type ID;

packages/babel-generator/test/fixtures/flow/declare-statements/output.js

@@ -22,17 +22,17 @@ declare class B {
   (): number
 }
 declare class A mixins B<T>, C {}
-declare type A = string;
+declare type A1 = string;
 declare type T<U> = {
   [k: string]: U
 };
-declare type B = {
+declare type B1 = {
   fn?: (foo: string) => void
 };
-declare interface I {
+declare interface I1 {
   foo: string
 }
-declare interface I<T> {
+declare interface I2<T> {
   foo: T
 }
 declare module.exports: {

packages/babel-generator/test/fixtures/flow/def-site-variance/input.js

@@ -5,10 +5,10 @@ type T2 = { +p: T };
 type T3 = { -p: T };
 type T4 = { +[k:K]: V };
 type T5 = { -[k:K]: V };
-interface I { +p: T }
-interface I { -p: T }
-interface I { +[k:K]: V }
-interface I { -[k:K]: V }
+interface I1 { +p: T }
+interface I2 { -p: T }
+interface I3 { +[k:K]: V }
+interface I4 { -[k:K]: V }
 declare class I { +p: T }
 declare class I { -p: T }
 declare class I { +[k:K]: V }

packages/babel-generator/test/fixtures/flow/def-site-variance/output.js

@@ -15,16 +15,16 @@ type T4 = {
 type T5 = {
   -[k: K]: V
 };
-interface I {
+interface I1 {
   +p: T
 }
-interface I {
+interface I2 {
   -p: T
 }
-interface I {
+interface I3 {
   +[k: K]: V
 }
-interface I {
+interface I4 {
   -[k: K]: V
 }
 declare class I {

packages/babel-generator/test/fixtures/flow/internal-slot/input.js

@@ -1,7 +1,7 @@
 declare class C { static [[foo]]: T }
 declare class C { [[foo]]: T }
-interface I { [[foo]]: X }
-interface I { [[foo]](): X }
+interface I1 { [[foo]]: X }
+interface I2 { [[foo]](): X }
 type T1 = { [[foo]]: X }
 type T2 = { [[foo]](): X }
 type T3 = { [[foo]]?: X }

packages/babel-generator/test/fixtures/flow/internal-slot/output.js

@@ -4,10 +4,10 @@ declare class C {
 declare class C {
   [[foo]]: T
 }
-interface I {
+interface I1 {
   [[foo]]: X
 }
-interface I {
+interface I2 {
   [[foo]]() => X
 }
 type T1 = {

packages/babel-generator/test/fixtures/flow/iterator-inside-interface/input.js

@@ -1,7 +1,7 @@
-interface A {
+interface A1 {
   @@iterator(): Iterator<File>;
 }
 
-interface A {
+interface A2 {
   @@asyncIterator(): Iterator<File>;
 }

packages/babel-generator/test/fixtures/flow/iterator-inside-interface/output.js

@@ -1,6 +1,6 @@
-interface A {
+interface A1 {
   @@iterator(): Iterator<File>
 }
-interface A {
+interface A2 {
   @@asyncIterator(): Iterator<File>
 }

packages/babel-parser/src/parser/expression.js

@@ -1944,7 +1944,7 @@ export default class ExpressionParser extends LValParser {
         node.params[i],
         BIND_VAR,
         allowDuplicates ? null : nameHash,
-        "function paramter list",
+        "function parameter list",
       );
     }
   }

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

@@ -14,6 +14,8 @@ import {
   type BindingTypes,
   BIND_NONE,
   BIND_LEXICAL,
+  BIND_VAR,
+  BIND_FUNCTION,
   SCOPE_ARROW,
   SCOPE_OTHER,
 } from "../util/scopeflags";
@@ -270,6 +272,7 @@ export default (superClass: Class<Parser>): Class<Parser> =>
       node.id = this.flowParseTypeAnnotatableIdentifier(
         /*allowPrimitiveOverride*/ true,
       );
+      this.scope.declareName(node.id.name, BIND_VAR, node.id.start);
       this.semicolon();
       return this.finishNode(node, "DeclareVariable");
     }
@@ -462,6 +465,12 @@ export default (superClass: Class<Parser>): Class<Parser> =>
     ): void {
       node.id = this.flowParseRestrictedIdentifier(/*liberal*/ !isClass);
 
+      this.scope.declareName(
+        node.id.name,
+        isClass ? BIND_FUNCTION : BIND_LEXICAL,
+        node.id.start,
+      );
+
       if (this.isRelational("<")) {
         node.typeParameters = this.flowParseTypeParameterDeclaration();
       } else {

packages/babel-parser/test/fixtures/flow/interfaces-module-and-script/implements-exports/input.js

@@ -0,0 +1,3 @@
+interface Foo {}
+
+export type { Foo }

packages/babel-parser/test/fixtures/flow/interfaces-module-and-script/implements-exports/output.json

@@ -0,0 +1,160 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 37,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 3,
+      "column": 19
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 37,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 3,
+        "column": 19
+      }
+    },
+    "sourceType": "module",
+    "interpreter": null,
+    "body": [
+      {
+        "type": "InterfaceDeclaration",
+        "start": 0,
+        "end": 16,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 16
+          }
+        },
+        "id": {
+          "type": "Identifier",
+          "start": 10,
+          "end": 13,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 10
+            },
+            "end": {
+              "line": 1,
+              "column": 13
+            },
+            "identifierName": "Foo"
+          },
+          "name": "Foo"
+        },
+        "typeParameters": null,
+        "extends": [],
+        "implements": [],
+        "mixins": [],
+        "body": {
+          "type": "ObjectTypeAnnotation",
+          "start": 14,
+          "end": 16,
+          "loc": {
+            "start": {
+              "line": 1,
+              "column": 14
+            },
+            "end": {
+              "line": 1,
+              "column": 16
+            }
+          },
+          "callProperties": [],
+          "properties": [],
+          "indexers": [],
+          "internalSlots": [],
+          "exact": false
+        }
+      },
+      {
+        "type": "ExportNamedDeclaration",
+        "start": 18,
+        "end": 37,
+        "loc": {
+          "start": {
+            "line": 3,
+            "column": 0
+          },
+          "end": {
+            "line": 3,
+            "column": 19
+          }
+        },
+        "specifiers": [
+          {
+            "type": "ExportSpecifier",
+            "start": 32,
+            "end": 35,
+            "loc": {
+              "start": {
+                "line": 3,
+                "column": 14
+              },
+              "end": {
+                "line": 3,
+                "column": 17
+              }
+            },
+            "local": {
+              "type": "Identifier",
+              "start": 32,
+              "end": 35,
+              "loc": {
+                "start": {
+                  "line": 3,
+                  "column": 14
+                },
+                "end": {
+                  "line": 3,
+                  "column": 17
+                },
+                "identifierName": "Foo"
+              },
+              "name": "Foo"
+            },
+            "exported": {
+              "type": "Identifier",
+              "start": 32,
+              "end": 35,
+              "loc": {
+                "start": {
+                  "line": 3,
+                  "column": 14
+                },
+                "end": {
+                  "line": 3,
+                  "column": 17
+                },
+                "identifierName": "Foo"
+              },
+              "name": "Foo"
+            }
+          }
+        ],
+        "source": null,
+        "exportKind": "type",
+        "declaration": null
+      }
+    ],
+    "directives": []
+  }
+}

packages/babel-parser/test/fixtures/flow/multiple-declarations/class/input.js

@@ -0,0 +1,2 @@
+declare class C1 {}
+class C1 {}

packages/babel-parser/test/fixtures/flow/multiple-declarations/class/options.json

@@ -0,0 +1,8 @@
+{
+  "sourceType": "module",
+  "plugins": [
+    "jsx",
+    "flow"
+  ],
+  "throws": "Identifier 'C1' has already been declared (2:6)"
+}

packages/babel-parser/test/fixtures/flow/multiple-declarations/declare-class/input.js

@@ -0,0 +1,6 @@
+declare class C1{}
+declare class C1{}
+
+declare module M1 {
+  declare class C1 {}
+}