AlignConsecutiveDeclarations not working for 'const' keyword in JavsScript

https://github.com/llvm/llvm-project/issues/49846

Fixes #49846

AlignConsecutiveDeclarations  is not working for "let" and "const" in JavaScript

let letVariable     = 5;
const constVariable = 10;

Reviewed By: owenpan, HazardyKnusperkeks, curdeius

Differential Revision: https://reviews.llvm.org/D115990

clang/include/clang/Format/Format.h

@@ -2669,6 +2669,7 @@ struct FormatStyle {
   bool isCpp() const { return Language == LK_Cpp || Language == LK_ObjC; }
   bool isCSharp() const { return Language == LK_CSharp; }
   bool isJson() const { return Language == LK_Json; }
+  bool isJavaScript() const { return Language == LK_JavaScript; }
 
   /// Language, this format style is targeted at.
   /// \version 3.5

clang/lib/Format/TokenAnnotator.cpp

@@ -1826,12 +1826,14 @@ private:
     if (Tok.Previous->isOneOf(TT_LeadingJavaAnnotation, Keywords.kw_instanceof,
                               Keywords.kw_as))
       return false;
-    if (Style.Language == FormatStyle::LK_JavaScript &&
+    if (Style.isJavaScript() && Tok.Previous->is(Keywords.kw_in))
-        Tok.Previous->is(Keywords.kw_in))
       return false;
 
     // Skip "const" as it does not have an influence on whether this is a name.
     FormatToken *PreviousNotConst = Tok.getPreviousNonComment();
+
+    // For javascript const can be like "let" or "var"
+    if (!Style.isJavaScript())
       while (PreviousNotConst && PreviousNotConst->is(tok::kw_const))
         PreviousNotConst = PreviousNotConst->getPreviousNonComment();
 
@@ -1852,10 +1854,24 @@ private:
         PreviousNotConst->is(TT_TypeDeclarationParen))
       return true;
 
-    return (!IsPPKeyword &&
+    // If is a preprocess keyword like #define.
-            PreviousNotConst->isOneOf(tok::identifier, tok::kw_auto)) ||
+    if (IsPPKeyword)
-           PreviousNotConst->is(TT_PointerOrReference) ||
+      return false;
-           PreviousNotConst->isSimpleTypeSpecifier();
+
+    // int a or auto a.
+    if (PreviousNotConst->isOneOf(tok::identifier, tok::kw_auto))
+      return true;
+
+    // *a or &a or &&a.
+    if (PreviousNotConst->is(TT_PointerOrReference))
+      return true;
+
+    // MyClass a;
+    if (PreviousNotConst->isSimpleTypeSpecifier())
+      return true;
+
+    // const a = in JavaScript.
+    return (Style.isJavaScript() && PreviousNotConst->is(tok::kw_const));
   }
 
   /// Determine whether ')' is ending a cast.

clang/unittests/Format/FormatTestJS.cpp

@@ -2696,5 +2696,115 @@ TEST_F(FormatTestJS, NumericSeparators) {
   verifyFormat("x = 1_000_000 + 12;", "x = 1_000_000   + 12;");
 }
 
+TEST_F(FormatTestJS, AlignConsecutiveDeclarations) {
+  FormatStyle Style = getGoogleStyle(FormatStyle::LK_JavaScript);
+  Style.AlignConsecutiveDeclarations = FormatStyle::ACS_Consecutive;
+  verifyFormat("let    letVariable = 5;\n"
+               "double constVariable = 10;",
+               Style);
+
+  verifyFormat("let   letVariable = 5;\n"
+               "const constVariable = 10;",
+               Style);
+
+  verifyFormat("let          letVariable = 5;\n"
+               "static const constVariable = 10;",
+               Style);
+
+  verifyFormat("let        letVariable = 5;\n"
+               "static var constVariable = 10;",
+               Style);
+
+  verifyFormat("let letVariable = 5;\n"
+               "var constVariable = 10;",
+               Style);
+
+  verifyFormat("double letVariable = 5;\n"
+               "var    constVariable = 10;",
+               Style);
+
+  verifyFormat("const letVariable = 5;\n"
+               "var   constVariable = 10;",
+               Style);
+
+  verifyFormat("int letVariable = 5;\n"
+               "int constVariable = 10;",
+               Style);
+}
+
+TEST_F(FormatTestJS, AlignConsecutiveAssignments) {
+  FormatStyle Style = getGoogleStyle(FormatStyle::LK_JavaScript);
+
+  Style.AlignConsecutiveAssignments = FormatStyle::ACS_Consecutive;
+  verifyFormat("let letVariable      = 5;\n"
+               "double constVariable = 10;",
+               Style);
+
+  verifyFormat("let letVariable     = 5;\n"
+               "const constVariable = 10;",
+               Style);
+
+  verifyFormat("let letVariable            = 5;\n"
+               "static const constVariable = 10;",
+               Style);
+
+  verifyFormat("let letVariable          = 5;\n"
+               "static var constVariable = 10;",
+               Style);
+
+  verifyFormat("let letVariable   = 5;\n"
+               "var constVariable = 10;",
+               Style);
+
+  verifyFormat("double letVariable = 5;\n"
+               "var constVariable  = 10;",
+               Style);
+
+  verifyFormat("const letVariable = 5;\n"
+               "var constVariable = 10;",
+               Style);
+
+  verifyFormat("int letVariable   = 5;\n"
+               "int constVariable = 10;",
+               Style);
+}
+
+TEST_F(FormatTestJS, AlignConsecutiveAssignmentsAndDeclarations) {
+  FormatStyle Style = getGoogleStyle(FormatStyle::LK_JavaScript);
+  Style.AlignConsecutiveDeclarations = FormatStyle::ACS_Consecutive;
+  Style.AlignConsecutiveAssignments = FormatStyle::ACS_Consecutive;
+  verifyFormat("let    letVariable   = 5;\n"
+               "double constVariable = 10;",
+               Style);
+
+  verifyFormat("let   letVariable   = 5;\n"
+               "const constVariable = 10;",
+               Style);
+
+  verifyFormat("let          letVariable   = 5;\n"
+               "static const constVariable = 10;",
+               Style);
+
+  verifyFormat("let        letVariable   = 5;\n"
+               "static var constVariable = 10;",
+               Style);
+
+  verifyFormat("let letVariable   = 5;\n"
+               "var constVariable = 10;",
+               Style);
+
+  verifyFormat("double letVariable   = 5;\n"
+               "var    constVariable = 10;",
+               Style);
+
+  verifyFormat("const letVariable   = 5;\n"
+               "var   constVariable = 10;",
+               Style);
+
+  verifyFormat("int letVariable   = 5;\n"
+               "int constVariable = 10;",
+               Style);
+}
+
 } // namespace format
 } // end namespace clang