fix(typescript): fix unstable optional method (#1770)

src/printer.js

@@ -2354,7 +2354,7 @@ function genericPrintNoParens(path, options, print, args) {
     case "TSMethodSignature":
       parts.push(
         path.call(print, "name"),
-        n.questionToken ? "?" : "",
+        n.questionToken && !n.name.optional ? "?" : "",
         printFunctionTypeParameters(path, options, print),
         printFunctionParams(path, print, options)
       );

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

@@ -0,0 +1,8 @@
+// Jest Snapshot v1, https://goo.gl/fbAQLP
+
+exports[`type_literal_optional_method.ts 1`] = `
+var v: { e?(): number };
+~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+var v: { e?(): number };
+
+`;

tests/typescript_method/jsfmt.spec.js

@@ -0,0 +1 @@
+run_spec(__dirname, { parser: "typescript" });

tests/typescript_method/type_literal_optional_method.ts

@@ -0,0 +1 @@
+var v: { e?(): number };