fixes #1114

- The visitor keys for `ObjectTypeAnnotation`s were incorrect so those nodes weren't being traversed so comments weren't attached for them.
 - The type parser wasn't eating the semicolons for the nodes so the `end` location of each of the type properties wasn't accurate which threw off the code generation newline algorithm.
 - Type properties hadn't been given the `UserWhitespacable` alias.

src/acorn/plugins/flow.js

@@ -215,6 +215,7 @@ pp.flow_parseObjectTypeIndexer = function (node, isStatic) {
   this.expect(tt.colon)
   node.value = this.flow_parseType()
 
+  this.flow_objectTypeSemicolon()
   return this.finishNode(node, "ObjectTypeIndexer")
 }
 
@@ -251,6 +252,7 @@ pp.flow_parseObjectTypeMethod = function (start, isStatic, key) {
   node.static = isStatic
   node.key = key
   node.optional = false
+  this.flow_objectTypeSemicolon()
   return this.finishNode(node, "ObjectTypeProperty")
 }
 
@@ -258,6 +260,7 @@ pp.flow_parseObjectTypeCallProperty = function (node, isStatic) {
   var valueNode = this.startNode()
   node.static = isStatic
   node.value = this.flow_parseObjectTypeMethodish(valueNode)
+    this.flow_objectTypeSemicolon()
   return this.finishNode(node, "ObjectTypeCallProperty")
 }
 
@@ -307,13 +310,10 @@ pp.flow_parseObjectType = function (allowStatic) {
         node.value = this.flow_parseType()
         node.optional = optional
         node.static = isStatic
+        this.flow_objectTypeSemicolon()
         nodeStart.properties.push(this.finishNode(node, "ObjectTypeProperty"))
       }
     }
-
-    if (!this.eat(tt.semi) && this.type !== tt.braceR) {
-      this.unexpected()
-    }
   }
 
   this.expect(tt.braceR)
@@ -321,6 +321,12 @@ pp.flow_parseObjectType = function (allowStatic) {
   return this.finishNode(nodeStart, "ObjectTypeAnnotation")
 }
 
+pp.flow_objectTypeSemicolon = function () {
+  if (!this.eat(tt.semi) && this.type !== tt.braceR) {
+    this.unexpected()
+  }
+}
+
 pp.flow_parseGenericType = function (start, id) {
   var node = this.startNodeAt(start)
 

src/babel/generation/generators/flow.js

@@ -167,17 +167,25 @@ export { TypeParameterInstantiation as TypeParameterDeclaration };
 export function ObjectTypeAnnotation(node, print) {
   this.push("{");
   var props = node.properties.concat(node.callProperties, node.indexers);
+
   if (props.length) {
     this.space();
-    print.list(props, { indent: true, separator: "; " });
+
+    print.list(props, {
+      separator: false,
+      indent: true
+    });
+
     this.space();
   }
+
   this.push("}");
 }
 
 export function ObjectTypeCallProperty(node, print) {
   if (node.static) this.push("static ");
   print(node.value);
+  this.semicolon();
 }
 
 export function ObjectTypeIndexer(node, print) {
@@ -191,6 +199,7 @@ export function ObjectTypeIndexer(node, print) {
   this.push(":");
   this.space();
   print(node.value);
+  this.semicolon();
 }
 
 export function ObjectTypeProperty(node, print) {
@@ -202,6 +211,7 @@ export function ObjectTypeProperty(node, print) {
     this.space();
   }
   print(node.value);
+  this.semicolon();
 }
 
 export function QualifiedTypeIdentifier(node, print) {

src/babel/generation/index.js

@@ -100,7 +100,7 @@ class CodeGenerator {
     };
 
     print.list = function (items, opts = {}) {
-      opts.separator ||= ", ";
+      if (opts.separator == null) opts.separator = ", ";
       print.join(items, opts);
     };
 

src/babel/types/alias-keys.json

@@ -98,9 +98,9 @@
   "TypeParameterDeclaration":    ["Flow"],
   "TypeParameterInstantiation":  ["Flow"],
   "ObjectTypeAnnotation":        ["Flow"],
-  "ObjectTypeCallProperty":      ["Flow"],
-  "ObjectTypeIndexer":           ["Flow"],
-  "ObjectTypeProperty":          ["Flow"],
+  "ObjectTypeCallProperty":      ["Flow", "UserWhitespacable"],
+  "ObjectTypeIndexer":           ["Flow", "UserWhitespacable"],
+  "ObjectTypeProperty":          ["Flow", "UserWhitespacable"],
   "QualifiedTypeIdentifier":     ["Flow"],
   "UnionTypeAnnotation":         ["Flow"],
   "VoidTypeAnnotation":          ["Flow"],

src/babel/types/visitor-keys.json

@@ -98,7 +98,7 @@
   "TypeCastExpression":          ["expression", "typeAnnotation"],
   "TypeParameterDeclaration":    ["params"],
   "TypeParameterInstantiation":  ["params"],
-  "ObjectTypeAnnotation":        ["key", "value"],
+  "ObjectTypeAnnotation":        ["properties", "indexers", "callProperties"],
   "ObjectTypeCallProperty":      ["value"],
   "ObjectTypeIndexer":           ["id", "key", "value"],
   "ObjectTypeProperty":          ["key", "value"],