Fix object and predicate annotations

index.js

@@ -37,6 +37,13 @@ module.exports = {
     //   }
     // });
     const ast = flowParser.parse(text);
+    if(ast.errors.length > 0) {
+      let msg = ast.errors[0].message + " on line " + ast.errors[0].loc.start.line
+      if(opts.filename) {
+        msg += " in file " + opts.filename;
+      }
+      throw new Error(msg);
+    }
 
     const printer = new Printer({ tabWidth, wrapColumn: printWidth });
     return printer.printGenerically(ast).code;

src/printer.js

@@ -356,8 +356,7 @@ function genericPrintNoParens(path, options, print) {
           softline,
           ")"
         ])),
-        path.call(print, "returnType"),
-        path.call(print, "predicate"),
+        printReturnType(path, print),
         " ",
         path.call(print, "body")
       );
@@ -378,6 +377,7 @@ function genericPrintNoParens(path, options, print) {
           !n.rest &&
           n.params[0].type === 'Identifier' &&
           !n.params[0].typeAnnotation &&
+          !n.predicate &&
           !n.returnType
       ) {
         parts.push(path.call(print, "params", 0));
@@ -386,7 +386,7 @@ function genericPrintNoParens(path, options, print) {
           "(",
           printFunctionParams(path, print),
           ")",
-          path.call(print, "returnType")
+          printReturnType(path, print)
         );
       }
 
@@ -650,7 +650,8 @@ function genericPrintNoParens(path, options, print) {
                    join(concat([separator, line]), props)
                  ])),
           line,
-          rightBrace
+          rightBrace,
+          path.call(print, "typeAnnotation")
         ]));
       }
 
@@ -798,7 +799,7 @@ function genericPrintNoParens(path, options, print) {
         " ",
         printed[0],
         indent(options.tabWidth,
-               join(concat([",", line]), printed.slice(1)))
+               concat(printed.slice(1).map(p => concat([",", line, p]))))
       ];
 
       // We generally want to terminate all variable declarations with a
@@ -1235,8 +1236,8 @@ function genericPrintNoParens(path, options, print) {
     case "Line": // Esprima line comment.
       return concat(["//", fromString(n.value, options)]);
 
-      // Type Annotations for Facebook Flow, typically stripped out or
-      // transformed away before printing.
+    // Type Annotations for Facebook Flow, typically stripped out or
+    // transformed away before printing.
     case "TypeAnnotation":
       if (n.typeAnnotation) {
         if (n.typeAnnotation.type !== "FunctionTypeAnnotation") {
@@ -1546,10 +1547,10 @@ function genericPrintNoParens(path, options, print) {
       return "null";
 
     case "InferredPredicate":
-      return ": %checks";
+      return "%checks";
 
     case "DeclaredPredicate":
-      return concat([": %checks(", path.call(print, "value"), ")"]);
+      return concat(["%checks(", path.call(print, "value"), ")"]);
 
       // Unhandled types below. If encountered, nodes of these types should
       // be either left alone or desugared into AST types that are fully
@@ -1680,7 +1681,7 @@ function printMethod(path, options, print) {
       return printFunctionParams(valuePath, print);
     }, "value"),
     ")",
-    path.call(print, "value", "returnType"),
+    path.call(p => printReturnType(p, print), "value"),
     " ",
     path.call(print, "value", "body")
   );
@@ -1766,7 +1767,7 @@ function printObjectMethod(path, options, print) {
     "(",
     printFunctionParams(path, print),
     ")",
-    path.call(print, "returnType"),
+    printReturnType(path, print),
     " ",
     path.call(print, "body")
   );
@@ -1774,6 +1775,20 @@ function printObjectMethod(path, options, print) {
   return concat(parts);
 }
 
+function printReturnType(path, print) {
+  const n = path.getValue();
+  const parts = [path.call(print, "returnType")];
+  if(n.predicate) {
+    parts.push(
+      // The return type will already add the colon, but otherwise we
+      // need to do it ourselves
+      n.returnType ? " " : ": ",
+      path.call(print, "predicate")
+    );
+  }
+  return concat(parts);
+}
+
 function printExportDeclaration(path, options, print) {
   var decl = path.getValue();
   var parts = ["export "];

tests/destructuring/__snapshots__/jsfmt.spec.js.snap

@@ -204,10 +204,10 @@ obj_rest();
 obj_rest({});
 obj_rest({ p: {} });
 obj_rest({ p: { q: 0, r: null } });
-function obj_prop_annot({ p } = { p: 0 }) {
+function obj_prop_annot({ p }: { p: string } = { p: 0 }) {
   (p: void);
 }
-var { p } = { p: 0 };
+var { p }: { p: string } = { p: 0 };
 (p: void);
 function obj_prop_err({ x: { y } } = null) {
   
@@ -221,21 +221,21 @@ function arr_elem_err([ x ] = null) {
 function arr_rest_err([ ...a ] = null) {
   
 }
-function gen<T>(x: T, { p }): T {
+function gen<T>(x: T, { p }: { p: T }): T {
   return p;
 }
 obj_prop_fun(({}: { p?: { q?: null } }));
 obj_prop_var(({}: { p?: { q?: null } }));
-function obj_prop_opt({ p } = { p: 0 }) {
+function obj_prop_opt({ p }: { p?: string } = { p: 0 }) {
   
 }
-function obj_prop_maybe({ p } = { p: 0 }) {
+function obj_prop_maybe({ p }: { p: ?string } = { p: 0 }) {
   
 }
-function obj_prop_union({ p } = { p: true }) {
+function obj_prop_union({ p }: { p: number | string } = { p: true }) {
   
 }
-function obj_prop_union2({ p } = { p: true }) {
+function obj_prop_union2({ p }: { p: number } | { p: string } = { p: true }) {
   
 }
 function default_expr_scope({ a, b }) {
@@ -351,11 +351,11 @@ function qux(_: { a: number }) {
   
 }
 qux({ a: \"\" });
-function corge({ b }) {
+function corge({ b }: { b: string }) {
   
 }
 corge({ b: 0 });
-var { n } = { n: \"\" };
+var { n }: { n: number } = { n: \"\" };
 function test() {
   var { foo } = { bar: 123 };
   var { bar, baz } = { bar: 123 };
@@ -392,23 +392,25 @@ exports[`test destructuring_param.js 1`] = `
   return a + b;
 }
 
-function g(a, { a }) {
-  return a;
-}
+// TODO: These throw errors when parsing.
+// function g(a, { a }) {
+//   return a;
+// }
 
-function h({ a, { b } }, { c }, { { d } }) {
-  return a + b + c + d;
-}
+// function h({ a, { b } }, { c }, { { d } }) {
+//   return a + b + c + d;
+// }
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+// TODO: These throw errors when parsing.
+// function g(a, { a }) {
+//   return a;
+// }
+// function h({ a, { b } }, { c }, { { d } }) {
+//   return a + b + c + d;
+// }
 function f(a, { b }) {
   return a + b;
 }
-function g(a, { a }) {
-  return a;
-}
-function h({ a, { }, ,, c, ,, { d }) {
-  return a + b + c + d;
-}
 "
 `;
 
@@ -469,11 +471,11 @@ function arr_rest_pattern<X>([ _, ...a ] : ArrRest<X>) { // a: [X]
 // o: { x: X }
 // a: [X]
 // a: [X]
-function obj_pattern<X>({ prop }) {
+function obj_pattern<X>({ prop }: { prop: X }) {
   
 }
 type Prop<X> = { prop: X };
-function obj_pattern2<X>({ prop }) {
+function obj_pattern2<X>({ prop }: Prop<X>) {
   
 }
 function arr_pattern<X>([ elem ]: X[]) {
@@ -496,11 +498,11 @@ function rest_antipattern<T>(...t: T) {
 function rest_pattern<X>(...r: X[]) {
   
 }
-function obj_rest_pattern<X>({ _, ...o }) {
+function obj_rest_pattern<X>({ _, ...o }: { _: any; x: X }) {
   o.x;
 }
 type ObjRest<X> = { _: any; x: X };
-function obj_rest_pattern<X>({ _, ...o }) {
+function obj_rest_pattern<X>({ _, ...o }: ObjRest<X>) {
   o.x;
 }
 function arr_rest_pattern<X>([ _, ...a ]: [any, X]) {

tests/destructuring/destructuring_param.js

@@ -2,10 +2,11 @@ function f(a, { b }) {
   return a + b;
 }
 
-function g(a, { a }) {
-  return a;
-}
+// TODO: These throw errors when parsing.
+// function g(a, { a }) {
+//   return a;
+// }
 
-function h({ a, { b } }, { c }, { { d } }) {
-  return a + b + c + d;
-}
+// function h({ a, { b } }, { c }, { { d } }) {
+//   return a + b + c + d;
+// }

tests/es6modules/__snapshots__/jsfmt.spec.js.snap

@@ -437,7 +437,7 @@ export var numberValue1 = 1, numberValue2 = 2;
  * @providesModule ES6_ExportFrom_Source1
  * @flow
  */
-export var numberValue1 = 1numberValue2 = 2;
+export var numberValue1 = 1, numberValue2 = 2;
 "
 `;
 
@@ -453,7 +453,7 @@ export var numberValue1 = 1, numberValue2 = 2;
  * @providesModule ES6_ExportFrom_Source2
  * @flow
  */
-export var numberValue1 = 1numberValue2 = 2;
+export var numberValue1 = 1, numberValue2 = 2;
 "
 `;
 
@@ -502,7 +502,7 @@ export class NumberGenerator {
     return 42;
   }
 }
-export var varDeclNumber1 = 1varDeclNumber2 = 2;
+export var varDeclNumber1 = 1, varDeclNumber2 = 2;
 export var { destructuredObjNumber } = { destructuredObjNumber: 1 };
 export var [ destructuredArrNumber ] = [ 1 ];
 "
@@ -549,7 +549,7 @@ export class NumberGenerator2 {
     return 42;
   }
 }
-export var varDeclNumber3 = 1varDeclNumber4 = 2;
+export var varDeclNumber3 = 1, varDeclNumber4 = 2;
 export var { destructuredObjNumber2 } = { destructuredObjNumber2: 1 };
 export var [ destructuredArrNumber2 ] = [ 1 ];
 "

tests/predicates-abstract/__snapshots__/jsfmt.spec.js.snap

@@ -57,8 +57,8 @@ type C = { kind: \"C\"; y: boolean };
 type D = { kind: \"D\"; x: boolean };
 type E = { kind: \"E\"; y: boolean };
 declare var ab: Array<A | B | C>;
-(my_filter(ab, x => x.kind === \"A\"): Array<A>);
-(my_filter(ab, x => x.kind !== \"A\"): Array<B | C>);
+(my_filter(ab, (x): %checks => x.kind === \"A\"): Array<A>);
+(my_filter(ab, (x): %checks => x.kind !== \"A\"): Array<B | C>);
 "
 `;
 
@@ -142,7 +142,7 @@ declare var d: mixed;
 var e = refine2(c, d, is_string_and_number);
 (e: string);
 declare function refine2<T, P: $Pred<2>>(v: T, w: T, cb: P): $Refine<T, P, 1>;
-function is_string(x): boolean: %checks {
+function is_string(x): boolean %checks {
   return typeof x === \"string\";
 }
 function is_string_and_number(x, y): %checks {
@@ -186,7 +186,7 @@ const b = my_filter(a, is_string);
 declare var c: Array<mixed>;
 const d = my_filter(c, is_string_regular);
 (d: Array<string>);
-function is_string(x): boolean: %checks {
+function is_string(x): boolean %checks {
   return typeof x === \"string\";
 }
 function is_string_regular(x): boolean {
@@ -226,8 +226,8 @@ type C = { kind: \"C\"; y: boolean };
 type D = { kind: \"D\"; x: boolean };
 type E = { kind: \"E\"; y: boolean };
 declare var ab: Array<A | B | C>;
-(my_filter(ab, x => x.kind === \"A\"): Array<B>);
-(my_filter(ab, x => x.kind !== \"A\"): Array<A | C>);
+(my_filter(ab, (x): %checks => x.kind === \"A\"): Array<B>);
+(my_filter(ab, (x): %checks => x.kind !== \"A\"): Array<A | C>);
 "
 `;
 

tests/predicates-declared/__snapshots__/jsfmt.spec.js.snap

@@ -407,7 +407,7 @@ function foo(x: string | Array<string>): string {
 // Sanity check:
 // - predicate functions cannot have bodies (can only be declarations)
 // error: cannot use pred type here
-function pred(x: mixed): boolean: %checks(typeof x === \"string\") {
+function pred(x: mixed): boolean %checks(typeof x === \"string\") {
   return typeof x === \"string\";
 }
 function foo(x: string | Array<string>): string {

tests/predicates-parsing/__snapshots__/jsfmt.spec.js.snap

@@ -35,7 +35,7 @@ var a2 = (x: mixed): %checks (x !== null) => {        // Error: body form
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 // @flow
 // Error: body form
-var a2 = (x: mixed) => {
+var a2 = (x: mixed): %checks(x !== null) => {
   var x = 1;
   return x;
 };
@@ -56,7 +56,7 @@ var a2 = (x: mixed): %checks (x !== null) => x !== null;
 function f5(x: mixed): %checks(x !== null) {
   return x !== null;
 }
-var a2 = (x: mixed) => x !== null;
+var a2 = (x: mixed): %checks(x !== null) => x !== null;
 "
 `;
 
@@ -97,9 +97,10 @@ function f7(x: mixed): %checks {
   return x !== null;
 }
 var a0 = (x: mixed) => x !== null;
-var a1 = (x: mixed) => x !== null;
-x => x !== null;
-const insert_a_really_big_predicated_arrow_function_name_here = x => x !== null;
+var a1 = (x: mixed): %checks => x !== null;
+(x): %checks => x !== null;
+const insert_a_really_big_predicated_arrow_function_name_here = (x): %checks => x !==
+  null;
 declare var x;
 x;
 checks => 123;

tests/unreachable/__snapshots__/jsfmt.spec.js.snap

@@ -88,8 +88,8 @@ function foo(x, y) {
   var baz = function(why) {
     return y + why;
   };
-  var xy, z;
-  var tu = 5, v, w = 7;
+  var x, y, z;
+  var t, u = 5, v, w = 7;
 }
 foo(1, 2);
 "