[PATCH] D29656: clang-format: [JS] correcly format object literal methods.

[Martin Probst via Phabricator via cfe-commits]

mprobst created this revision.
Herald added a subscriber: klimek.

In JavaScript, object literals can contain methods:

  var x = {
    a() { return 1; },
  };

Previously, clang-format always parsed nested {} inside a braced list as
further braced lists. Special case this logic for JavaScript to try
parsing as a braced list, but fall back to parsing as a child block.


https://reviews.llvm.org/D29656

Files:
  lib/Format/TokenAnnotator.cpp
  lib/Format/UnwrappedLineParser.cpp
  unittests/Format/FormatTestJS.cpp


Index: unittests/Format/FormatTestJS.cpp
===================================================================
--- unittests/Format/FormatTestJS.cpp
+++ unittests/Format/FormatTestJS.cpp
@@ -240,6 +240,18 @@
                "};");
   verifyFormat("var x = {y: (a) => a};");
 
+  // Methods in object literals.
+  verifyFormat("var x = {\n"
+               "  y(a: string): number {\n"
+               "    return a;\n"
+               "  }\n"
+               "};");
+  verifyFormat("var x = {\n"
+               "  y(a: string) {\n"
+               "    return a;\n"
+               "  }\n"
+               "};");
+
   // Computed keys.
   verifyFormat("var x = {[a]: 1, b: 2, [c]: 3};");
   verifyFormat("var x = {\n"
Index: lib/Format/UnwrappedLineParser.cpp
===================================================================
--- lib/Format/UnwrappedLineParser.cpp
+++ lib/Format/UnwrappedLineParser.cpp
@@ -335,8 +335,11 @@
     case tok::l_brace:
       if (Style.Language == FormatStyle::LK_JavaScript && PrevTok &&
           PrevTok->is(tok::colon))
-        // In TypeScript's TypeMemberLists, there can be semicolons between the
-        // individual members.
+        // A colon indicates this code is in a type, or a braced list following
+        // a label in an object literal ({a: {b: 1}}).
+        // The code below could be confused by semicolons between the individual
+        // members in a type member list, which would normally trigger BK_Block.
+        // In both cases, this must be parsed as an inline braced init.
         Tok->BlockKind = BK_BracedInit;
       else
         Tok->BlockKind = BK_Unknown;
@@ -1298,6 +1301,13 @@
           continue;
         }
       }
+      if (FormatTok->is(tok::l_brace)) {
+        // Could be a method inside of a braced list `{a() { return 1; }}`.
+        if (tryToParseBracedList()) {
+          continue;
+        }
+        parseChildBlock();
+      }
     }
     switch (FormatTok->Tok.getKind()) {
     case tok::caret:
@@ -1309,12 +1319,6 @@
     case tok::l_square:
       tryToParseLambda();
       break;
-    case tok::l_brace:
-      // Assume there are no blocks inside a braced init list apart
-      // from the ones we explicitly parse out (like lambdas).
-      FormatTok->BlockKind = BK_BracedInit;
-      parseBracedList();
-      break;
     case tok::l_paren:
       parseParens();
       // JavaScript can just have free standing methods and getters/setters in
@@ -1325,6 +1329,12 @@
         break;
       }
       break;
+    case tok::l_brace:
+      // Assume there are no blocks inside a braced init list apart
+      // from the ones we explicitly parse out (like lambdas).
+      FormatTok->BlockKind = BK_BracedInit;
+      parseBracedList();
+      break;
     case tok::r_brace:
       nextToken();
       return !HasError;
Index: lib/Format/TokenAnnotator.cpp
===================================================================
--- lib/Format/TokenAnnotator.cpp
+++ lib/Format/TokenAnnotator.cpp
@@ -2648,6 +2648,7 @@
                  << " T=" << getTokenTypeName(Tok->Type)
                  << " S=" << Tok->SpacesRequiredBefore
                  << " B=" << Tok->BlockParameterCount
+                 << " BK=" << Tok->BlockKind
                  << " P=" << Tok->SplitPenalty << " Name=" << Tok->Tok.getName()
                  << " L=" << Tok->TotalLength << " PPK=" << Tok->PackingKind
                  << " FakeLParens=";


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