From db85bdc3fccd3bf1ffead68a2f77e1adf091934e Mon Sep 17 00:00:00 2001
From: Sam Pepose <sampepose@gmail.com>
Date: Tue, 15 Nov 2016 13:43:42 -0600
Subject: [PATCH] Added flowCommaSeparator option for object types (#3547)

---
 packages/babel-generator/README.md                     |  1 +
 packages/babel-generator/src/generators/flow.js        |  6 +++++-
 packages/babel-generator/src/index.js                  |  3 ++-
 .../fixtures/flowUsesCommas/ObjectExpression/actual.js | 10 ++++++++++
 .../flowUsesCommas/ObjectExpression/expected.js        | 10 ++++++++++
 .../test/fixtures/flowUsesCommas/options.json          |  3 +++
 6 files changed, 31 insertions(+), 2 deletions(-)
 create mode 100644 packages/babel-generator/test/fixtures/flowUsesCommas/ObjectExpression/actual.js
 create mode 100644 packages/babel-generator/test/fixtures/flowUsesCommas/ObjectExpression/expected.js
 create mode 100644 packages/babel-generator/test/fixtures/flowUsesCommas/options.json

diff --git a/packages/babel-generator/README.md b/packages/babel-generator/README.md
index 5de763278c..176b7649ca 100644
--- a/packages/babel-generator/README.md
+++ b/packages/babel-generator/README.md
@@ -37,6 +37,7 @@ minified               | boolean  | `false`         | Should the output be minif
 concise                | boolean  | `false`         | Set to `true` to reduce whitespace (but not as much as `opts.compact`)
 quotes                 | `'single'` or `'double'` | autodetect based on `ast.tokens` | The type of quote to use in the output
 filename               | string   |                 | Used in warning messages
+flowCommaSeparator     | boolean  | `false`         | Set to `true` to use commas instead of semicolons as Flow property separators
 
 Options for source maps:
 
diff --git a/packages/babel-generator/src/generators/flow.js b/packages/babel-generator/src/generators/flow.js
index b6c5a8b20d..4a03b21a6b 100644
--- a/packages/babel-generator/src/generators/flow.js
+++ b/packages/babel-generator/src/generators/flow.js
@@ -274,7 +274,11 @@ export function ObjectTypeAnnotation(node: Object) {
       statement: true,
       iterator: () => {
         if (props.length !== 1) {
-          this.semicolon();
+          if (this.format.flowCommaSeparator) {
+            this.token(",");
+          } else {
+            this.semicolon();
+          }
           this.space();
         }
       }
diff --git a/packages/babel-generator/src/index.js b/packages/babel-generator/src/index.js
index 714f21d748..b4442b27e2 100644
--- a/packages/babel-generator/src/index.js
+++ b/packages/babel-generator/src/index.js
@@ -63,7 +63,8 @@ function normalizeOptions(code, opts, tokens): Format {
       adjustMultilineComment: true,
       style: style,
       base: 0
-    }
+    },
+    flowCommaSeparator: opts.flowCommaSeparator,
   };
 
   if (format.minified) {
diff --git a/packages/babel-generator/test/fixtures/flowUsesCommas/ObjectExpression/actual.js b/packages/babel-generator/test/fixtures/flowUsesCommas/ObjectExpression/actual.js
new file mode 100644
index 0000000000..b25558906e
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/flowUsesCommas/ObjectExpression/actual.js
@@ -0,0 +1,10 @@
+var a: { numVal: number };
+var a: { numVal: number; };
+var a: { numVal: number; [indexer: string]: number };
+var a: ?{ numVal: number };
+var a: { numVal: number; strVal: string }
+var a: { subObj: {strVal: string} }
+var a: { subObj: ?{strVal: string} }
+var a: { param1: number; param2: string }
+var a: { param1: number; param2?: string }
+var a: { [a: number]: string; [b: number]: string; };
diff --git a/packages/babel-generator/test/fixtures/flowUsesCommas/ObjectExpression/expected.js b/packages/babel-generator/test/fixtures/flowUsesCommas/ObjectExpression/expected.js
new file mode 100644
index 0000000000..69dd9891bb
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/flowUsesCommas/ObjectExpression/expected.js
@@ -0,0 +1,10 @@
+var a: { numVal: number };
+var a: { numVal: number };
+var a: { numVal: number, [indexer: string]: number, };
+var a: ?{ numVal: number };
+var a: { numVal: number, strVal: string, };
+var a: { subObj: { strVal: string } };
+var a: { subObj: ?{ strVal: string } };
+var a: { param1: number, param2: string, };
+var a: { param1: number, param2?: string, };
+var a: { [a: number]: string, [b: number]: string, };
diff --git a/packages/babel-generator/test/fixtures/flowUsesCommas/options.json b/packages/babel-generator/test/fixtures/flowUsesCommas/options.json
new file mode 100644
index 0000000000..f50690ec13
--- /dev/null
+++ b/packages/babel-generator/test/fixtures/flowUsesCommas/options.json
@@ -0,0 +1,3 @@
+{
+  "flowCommaSeparator": true
+}