From 3524ad510f9927b99399c7feadb7bdfd97333bb6 Mon Sep 17 00:00:00 2001
From: Sebastian McKenzie <sebmck@gmail.com>
Date: Wed, 22 Jun 2016 13:43:32 +0100
Subject: [PATCH] remove grouped type arrow restriction as it seems flow no
 longer has it - fixes #44

---
 src/plugins/flow.js                           |  14 -
 .../existential-type-param-2/actual.js        |   1 +
 .../existential-type-param-2/expected.json    | 260 ++++++++++++++++++
 3 files changed, 261 insertions(+), 14 deletions(-)
 create mode 100644 test/fixtures/flow/type-annotations/existential-type-param-2/actual.js
 create mode 100644 test/fixtures/flow/type-annotations/existential-type-param-2/expected.json

diff --git a/src/plugins/flow.js b/src/plugins/flow.js
index 23aa49e175..9d0279ae99 100644
--- a/src/plugins/flow.js
+++ b/src/plugins/flow.js
@@ -517,20 +517,6 @@ pp.flowParsePrimaryType = function () {
       if (isGroupedType) {
         type = this.flowParseType();
         this.expect(tt.parenR);
-
-        // If we see a => next then someone was probably confused about
-        // function types, so we can provide a better error message
-        if (this.eat(tt.arrow)) {
-          this.raise(node,
-            "Unexpected token =>. It looks like " +
-            "you are trying to write a function type, but you ended up " +
-            "writing a grouped type followed by an =>, which is a syntax " +
-            "error. Remember, function type parameters are named so function " +
-            "types look like (name1: type1, name2: type2) => returnType. You " +
-            "probably wrote (type1) => returnType"
-          );
-        }
-
         return type;
       }
 
diff --git a/test/fixtures/flow/type-annotations/existential-type-param-2/actual.js b/test/fixtures/flow/type-annotations/existential-type-param-2/actual.js
new file mode 100644
index 0000000000..a97ae6fc54
--- /dev/null
+++ b/test/fixtures/flow/type-annotations/existential-type-param-2/actual.js
@@ -0,0 +1 @@
+let f : * = (x : null | *) : (*) => {}
diff --git a/test/fixtures/flow/type-annotations/existential-type-param-2/expected.json b/test/fixtures/flow/type-annotations/existential-type-param-2/expected.json
new file mode 100644
index 0000000000..c9047516f4
--- /dev/null
+++ b/test/fixtures/flow/type-annotations/existential-type-param-2/expected.json
@@ -0,0 +1,260 @@
+{
+  "type": "File",
+  "start": 0,
+  "end": 38,
+  "loc": {
+    "start": {
+      "line": 1,
+      "column": 0
+    },
+    "end": {
+      "line": 1,
+      "column": 38
+    }
+  },
+  "program": {
+    "type": "Program",
+    "start": 0,
+    "end": 38,
+    "loc": {
+      "start": {
+        "line": 1,
+        "column": 0
+      },
+      "end": {
+        "line": 1,
+        "column": 38
+      }
+    },
+    "sourceType": "module",
+    "body": [
+      {
+        "type": "VariableDeclaration",
+        "start": 0,
+        "end": 38,
+        "loc": {
+          "start": {
+            "line": 1,
+            "column": 0
+          },
+          "end": {
+            "line": 1,
+            "column": 38
+          }
+        },
+        "declarations": [
+          {
+            "type": "VariableDeclarator",
+            "start": 4,
+            "end": 38,
+            "loc": {
+              "start": {
+                "line": 1,
+                "column": 4
+              },
+              "end": {
+                "line": 1,
+                "column": 38
+              }
+            },
+            "id": {
+              "type": "Identifier",
+              "start": 4,
+              "end": 9,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 4
+                },
+                "end": {
+                  "line": 1,
+                  "column": 9
+                }
+              },
+              "name": "f",
+              "typeAnnotation": {
+                "type": "TypeAnnotation",
+                "start": 6,
+                "end": 9,
+                "loc": {
+                  "start": {
+                    "line": 1,
+                    "column": 6
+                  },
+                  "end": {
+                    "line": 1,
+                    "column": 9
+                  }
+                },
+                "typeAnnotation": {
+                  "type": "ExistentialTypeParam",
+                  "start": 8,
+                  "end": 9,
+                  "loc": {
+                    "start": {
+                      "line": 1,
+                      "column": 8
+                    },
+                    "end": {
+                      "line": 1,
+                      "column": 9
+                    }
+                  }
+                }
+              }
+            },
+            "init": {
+              "type": "ArrowFunctionExpression",
+              "start": 12,
+              "end": 38,
+              "loc": {
+                "start": {
+                  "line": 1,
+                  "column": 12
+                },
+                "end": {
+                  "line": 1,
+                  "column": 38
+                }
+              },
+              "returnType": {
+                "type": "TypeAnnotation",
+                "start": 27,
+                "end": 32,
+                "loc": {
+                  "start": {
+                    "line": 1,
+                    "column": 27
+                  },
+                  "end": {
+                    "line": 1,
+                    "column": 32
+                  }
+                },
+                "typeAnnotation": {
+                  "type": "ExistentialTypeParam",
+                  "start": 30,
+                  "end": 31,
+                  "loc": {
+                    "start": {
+                      "line": 1,
+                      "column": 30
+                    },
+                    "end": {
+                      "line": 1,
+                      "column": 31
+                    }
+                  }
+                }
+              },
+              "id": null,
+              "generator": false,
+              "expression": false,
+              "async": false,
+              "params": [
+                {
+                  "type": "Identifier",
+                  "start": 13,
+                  "end": 14,
+                  "loc": {
+                    "start": {
+                      "line": 1,
+                      "column": 13
+                    },
+                    "end": {
+                      "line": 1,
+                      "column": 14
+                    }
+                  },
+                  "name": "x",
+                  "typeAnnotation": {
+                    "type": "TypeAnnotation",
+                    "start": 15,
+                    "end": 25,
+                    "loc": {
+                      "start": {
+                        "line": 1,
+                        "column": 15
+                      },
+                      "end": {
+                        "line": 1,
+                        "column": 25
+                      }
+                    },
+                    "typeAnnotation": {
+                      "type": "UnionTypeAnnotation",
+                      "start": 17,
+                      "end": 25,
+                      "loc": {
+                        "start": {
+                          "line": 1,
+                          "column": 17
+                        },
+                        "end": {
+                          "line": 1,
+                          "column": 25
+                        }
+                      },
+                      "types": [
+                        {
+                          "type": "NullLiteralTypeAnnotation",
+                          "start": 17,
+                          "end": 21,
+                          "loc": {
+                            "start": {
+                              "line": 1,
+                              "column": 17
+                            },
+                            "end": {
+                              "line": 1,
+                              "column": 21
+                            }
+                          },
+                          "value": true
+                        },
+                        {
+                          "type": "ExistentialTypeParam",
+                          "start": 24,
+                          "end": 25,
+                          "loc": {
+                            "start": {
+                              "line": 1,
+                              "column": 24
+                            },
+                            "end": {
+                              "line": 1,
+                              "column": 25
+                            }
+                          }
+                        }
+                      ]
+                    }
+                  }
+                }
+              ],
+              "body": {
+                "type": "BlockStatement",
+                "start": 36,
+                "end": 38,
+                "loc": {
+                  "start": {
+                    "line": 1,
+                    "column": 36
+                  },
+                  "end": {
+                    "line": 1,
+                    "column": 38
+                  }
+                },
+                "body": [],
+                "directives": []
+              }
+            }
+          }
+        ],
+        "kind": "let"
+      }
+    ],
+    "directives": []
+  }
+}
\ No newline at end of file