JS: fix !"" => true, fixes #723

tdewolff · Jul 10, 2024 · 3354711 · 3354711
1 parent ba78373
commit 3354711
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/js/js.go b/js/js.go
@@ -1010,8 +1010,17 @@ func (m *jsMinifier) minifyExpr(i js.IExpr, prec js.OpPrec) {
 				// <!--  =>  <! --
 				m.writeSpaceBefore('-')
 			} else if expr.Op == js.NotToken {
-				if lit, ok := expr.X.(*js.LiteralExpr); ok && (lit.TokenType == js.StringToken || lit.TokenType == js.RegExpToken) {
-					// !"string"  =>  !1
+				if lit, ok := expr.X.(*js.LiteralExpr); ok && lit.TokenType == js.StringToken {
+					if len(lit.Data) == 2 {
+						// !""  =>  !0
+						m.write(zeroBytes)
+					} else {
+						// !"string"  =>  !1
+						m.write(oneBytes)
+					}
+					break
+				} else if ok && lit.TokenType == js.RegExpToken {
+					// !/regexp/  =>  !1
 					m.write(oneBytes)
 					break
 				} else if ok && (lit.TokenType == js.DecimalToken || lit.TokenType == js.IntegerToken) {

diff --git a/js/js_test.go b/js/js_test.go
@@ -195,6 +195,8 @@ func TestJS(t *testing.T) {
 		{`x=Infinity()`, `x=(1/0)()`},
 		{`x=2**Infinity`, `x=2**(1/0)`},
 		//{`Infinity=5;x=Infinity`, `Infinity=5;x=Infinity`},
+		{`!""`, `!0`},
+		{`!"foobar"`, `!1`},
 		{`class a extends undefined {}`, `class a extends(void 0){}`},
 		{`new true`, `new(!0)`},
 		{`function*a(){yield undefined}`, `function*a(){yield}`},