clang-format: [JS] more precisely detect enums.

The current enum detection is overly aggressive. As NestingLevel only
applies per line (?) it classifies many if not most object literals as
enum declarations and adds superfluous line breaks into them. This
change narrows the heuristic by requiring an assignment just before the
open brace and requiring the line to start with an identifier.

Patch by Martin Probst. Thank you.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@232320 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Format/TokenAnnotator.cpp b/lib/Format/TokenAnnotator.cpp
index caca6458df4f5c665c731d7dc5356eb6673917f7..c6c81a48912c6fac44af935d32661af7c997001f 100644 (file)
--- a/lib/Format/TokenAnnotator.cpp
+++ b/lib/Format/TokenAnnotator.cpp
@@ -1952,7 +1952,13 @@ bool TokenAnnotator::mustBreakBefore(const AnnotatedLine &Line,
         Left.Previous->is(tok::char_constant))
       return true;
     if (Left.is(TT_DictLiteral) && Left.is(tok::l_brace) &&
-        Left.NestingLevel == 0)
+        Left.NestingLevel == 0 && Left.Previous &&
+        Left.Previous->is(tok::equal) &&
+        Line.First->isOneOf(tok::identifier, Keywords.kw_import,
+                            tok::kw_export) &&
+        // kw_var is a pseudo-token that's a tok::identifier, so matches above.
+        !Line.First->is(Keywords.kw_var))
+      // Enum style object literal.
       return true;
   } else if (Style.Language == FormatStyle::LK_Java) {
     if (Right.is(tok::plus) && Left.is(tok::string_literal) && Right.Next &&

diff --git a/unittests/Format/FormatTestJS.cpp b/unittests/Format/FormatTestJS.cpp
index 55e89da6216881062a1e04960fffbb3e89e8d71f..045b280f18758ede0b51e13233d71a6c9e9653bb 100644 (file)
--- a/unittests/Format/FormatTestJS.cpp
+++ b/unittests/Format/FormatTestJS.cpp
@@ -94,10 +94,7 @@ TEST_F(FormatTestJS, LiteralOperatorsCanBeKeywords) {
 
 TEST_F(FormatTestJS, ES6DestructuringAssignment) {
   verifyFormat("var [a, b, c] = [1, 2, 3];");
-  verifyFormat("var {a, b} = {\n"
-               "  a: 1,\n"
-               "  b: 2\n"
-               "};");
+  verifyFormat("var {a, b} = {a: 1, b: 2};");
 }
 
 TEST_F(FormatTestJS, ContainerLiterals) {
@@ -139,6 +136,12 @@ TEST_F(FormatTestJS, ContainerLiterals) {
                "    return x.zIsTooLongForOneLineWithTheDeclarationLine();\n"
                "  }\n"
                "};");
+  // Simple object literal, as opposed to enum style below.
+  verifyFormat("var obj = {a: 123};");
+  // Enum style top level assignment.
+  verifyFormat("X = {\n  a: 123\n};");
+  verifyFormat("X.Y = {\n  a: 123\n};");
+  verifyFormat("x = foo && {a: 123};");
 }
 
 TEST_F(FormatTestJS, SpacesInContainerLiterals) {
@@ -545,7 +548,7 @@ TEST_F(FormatTestJS, Modules) {
                getGoogleJSStyleWithColumns(20));
   verifyFormat("import {X as myLocalX, Y as myLocalY} from 'some/module.js';");
   verifyFormat("import * as lib from 'some/module.js';");
-  verifyFormat("var x = {\n  import: 1\n};\nx.import = 2;");
+  verifyFormat("var x = {import: 1};\nx.import = 2;");
 
   verifyFormat("export function fn() {\n"
                "  return 'fn';\n"