JS: merge sequential var declarations into another declaration

tdewolff · Apr 2, 2022 · e7fcbe9 · e7fcbe9
1 parent 2a0dc90
commit e7fcbe9
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Showing 2 changed files with 11 additions and 1 deletion.
diff --git a/js/js_test.go b/js/js_test.go
@@ -334,6 +334,10 @@ func TestJS(t *testing.T) {
 		{`var a,b=c;b=a`, `var a,b=c;b=a`},
 		{`var{a}=f;var b=c,d=e;`, `var{a}=f,b=c,d=e`},
 		{`var a,b;a=1,b=2,c=3`, `var a=1,b=2;c=3`},
+		{`var a=[];var b={};var c=d,e=f`, `var a=[],b={},c=d,e=f`},
+		{`var a=[];var b={};var c=d,e=f`, `var a=[],b={},c=d,e=f`},
+		{`var a=[];var b;var c,e=f`, `var a=[],b,c,e=f`},
+		{`var a=[];f();var b;f();var c;f();var e=f`, `var a=[],b,c,e;f(),f(),f(),e=f`},
 		// TODO: test for variables renaming (first rename, then merge vars)
 
 		// function and method declarations

diff --git a/js/vars.go b/js/vars.go
@@ -261,7 +261,13 @@ func mergeVarDeclExprStmt(decl *js.VarDecl, exprStmt *js.ExprStmt, forward bool)
 			if forward {
 				item = commaExpr.List[len(commaExpr.List)-i-1]
 			}
-			if binaryExpr, ok := item.(*js.BinaryExpr); ok && binaryExpr.Op == js.EqToken {
+			if src, ok := item.(*js.VarDecl); ok {
+				// this happens when a variable declarations is converted to an expression
+				if mergeVarDecls(decl, src, forward) {
+					n++
+					continue
+				}
+			} else if binaryExpr, ok := item.(*js.BinaryExpr); ok && binaryExpr.Op == js.EqToken {
 				if v, ok := binaryExpr.X.(*js.Var); ok && v.Decl == js.VariableDecl {
 					if addDefinition(decl, v, binaryExpr.Y, forward) {
 						n++