avoid cast and accept baseline

Author: Kingwl

src/compiler/checker.ts

@@ -4974,12 +4974,11 @@ namespace ts {
         }
 
         function isStringConcatExpression(expr: Node): boolean {
-            if (expr.kind === SyntaxKind.StringLiteral) {
+            if (isStringLiteral(expr)) {
                 return true;
             }
-            else if (expr.kind === SyntaxKind.BinaryExpression) {
-                const binaryExpression = <BinaryExpression>expr;
-                return binaryExpression.operatorToken.kind === SyntaxKind.PlusToken && isStringConcatExpression(binaryExpression.left) && isStringConcatExpression(binaryExpression.right);
+            else if (isBinaryExpression(expr)) {
+                return expr.operatorToken.kind === SyntaxKind.PlusToken && isStringConcatExpression(expr.left) && isStringConcatExpression(expr.right);
             }
             return false;
         }

tests/baselines/reference/enumConstantMemberWithStringDeclaration.js

@@ -0,0 +1,82 @@
+//// [enumConstantMemberWithStringDeclaration.ts]
+enum T1 {
+    a = "1",
+    b = "1" + "2",
+    c = "1" + "2" + "3"
+}
+
+enum T2 {
+    a = "1",
+    b = "1" + "2"
+}
+
+enum T3 {
+    a = "1",
+    b = "1" + "2"
+}
+
+enum T4 {
+    a = "1"
+}
+
+enum T5 {
+    a = "1" + "2"
+}
+
+declare enum T6 {
+    a = "1",
+    b = "1" + "2"
+}
+
+
+//// [enumConstantMemberWithStringDeclaration.js]
+var T1;
+(function (T1) {
+    T1["a"] = "1";
+    T1["b"] = "12";
+    T1["c"] = "123";
+})(T1 || (T1 = {}));
+var T2;
+(function (T2) {
+    T2["a"] = "1";
+    T2["b"] = "12";
+})(T2 || (T2 = {}));
+var T3;
+(function (T3) {
+    T3["a"] = "1";
+    T3["b"] = "12";
+})(T3 || (T3 = {}));
+var T4;
+(function (T4) {
+    T4["a"] = "1";
+})(T4 || (T4 = {}));
+var T5;
+(function (T5) {
+    T5["a"] = "12";
+})(T5 || (T5 = {}));
+
+
+//// [enumConstantMemberWithStringDeclaration.d.ts]
+declare enum T1 {
+    a = "1",
+    b = "12",
+    c = "123",
+}
+declare enum T2 {
+    a = "1",
+    b = "12",
+}
+declare enum T3 {
+    a = "1",
+    b = "12",
+}
+declare enum T4 {
+    a = "1",
+}
+declare enum T5 {
+    a = "12",
+}
+declare enum T6 {
+    a = "1",
+    b = "12",
+}

tests/baselines/reference/enumConstantMemberWithStringDeclaration.symbols

@@ -0,0 +1,58 @@
+=== tests/cases/conformance/enums/enumConstantMemberWithStringDeclaration.ts ===
+enum T1 {
+>T1 : Symbol(T1, Decl(enumConstantMemberWithStringDeclaration.ts, 0, 0))
+
+    a = "1",
+>a : Symbol(T1.a, Decl(enumConstantMemberWithStringDeclaration.ts, 0, 9))
+
+    b = "1" + "2",
+>b : Symbol(T1.b, Decl(enumConstantMemberWithStringDeclaration.ts, 1, 12))
+
+    c = "1" + "2" + "3"
+>c : Symbol(T1.c, Decl(enumConstantMemberWithStringDeclaration.ts, 2, 18))
+}
+
+enum T2 {
+>T2 : Symbol(T2, Decl(enumConstantMemberWithStringDeclaration.ts, 4, 1))
+
+    a = "1",
+>a : Symbol(T2.a, Decl(enumConstantMemberWithStringDeclaration.ts, 6, 9))
+
+    b = "1" + "2"
+>b : Symbol(T2.b, Decl(enumConstantMemberWithStringDeclaration.ts, 7, 12))
+}
+
+enum T3 {
+>T3 : Symbol(T3, Decl(enumConstantMemberWithStringDeclaration.ts, 9, 1))
+
+    a = "1",
+>a : Symbol(T3.a, Decl(enumConstantMemberWithStringDeclaration.ts, 11, 9))
+
+    b = "1" + "2"
+>b : Symbol(T3.b, Decl(enumConstantMemberWithStringDeclaration.ts, 12, 12))
+}
+
+enum T4 {
+>T4 : Symbol(T4, Decl(enumConstantMemberWithStringDeclaration.ts, 14, 1))
+
+    a = "1"
+>a : Symbol(T4.a, Decl(enumConstantMemberWithStringDeclaration.ts, 16, 9))
+}
+
+enum T5 {
+>T5 : Symbol(T5, Decl(enumConstantMemberWithStringDeclaration.ts, 18, 1))
+
+    a = "1" + "2"
+>a : Symbol(T5.a, Decl(enumConstantMemberWithStringDeclaration.ts, 20, 9))
+}
+
+declare enum T6 {
+>T6 : Symbol(T6, Decl(enumConstantMemberWithStringDeclaration.ts, 22, 1))
+
+    a = "1",
+>a : Symbol(T6.a, Decl(enumConstantMemberWithStringDeclaration.ts, 24, 17))
+
+    b = "1" + "2"
+>b : Symbol(T6.b, Decl(enumConstantMemberWithStringDeclaration.ts, 25, 12))
+}
+

tests/baselines/reference/enumConstantMemberWithStringDeclaration.types

@@ -0,0 +1,83 @@
+=== tests/cases/conformance/enums/enumConstantMemberWithStringDeclaration.ts ===
+enum T1 {
+>T1 : T1
+
+    a = "1",
+>a : T1.a
+>"1" : "1"
+
+    b = "1" + "2",
+>b : T1.b
+>"1" + "2" : string
+>"1" : "1"
+>"2" : "2"
+
+    c = "1" + "2" + "3"
+>c : T1.c
+>"1" + "2" + "3" : string
+>"1" + "2" : string
+>"1" : "1"
+>"2" : "2"
+>"3" : "3"
+}
+
+enum T2 {
+>T2 : T2
+
+    a = "1",
+>a : T2.a
+>"1" : "1"
+
+    b = "1" + "2"
+>b : T2.b
+>"1" + "2" : string
+>"1" : "1"
+>"2" : "2"
+}
+
+enum T3 {
+>T3 : T3
+
+    a = "1",
+>a : T3.a
+>"1" : "1"
+
+    b = "1" + "2"
+>b : T3.b
+>"1" + "2" : string
+>"1" : "1"
+>"2" : "2"
+}
+
+enum T4 {
+>T4 : T4
+
+    a = "1"
+>a : T4
+>"1" : "1"
+}
+
+enum T5 {
+>T5 : T5
+
+    a = "1" + "2"
+>a : T5
+>"1" + "2" : string
+>"1" : "1"
+>"2" : "2"
+}
+
+declare enum T6 {
+>T6 : T6
+
+    a = "1",
+>a : T6.a
+>"1" : "1"
+
+    b = "1" + "2"
+>b : T6.b
+>"1" + "2" : string
+>"1" : "1"
+>"2" : "2"
+}
+

tests/cases/conformance/enums/enumConstantMemberWithStringDeclaration.ts

@@ -0,0 +1,29 @@
+// @declaration: true
+enum T1 {
+    a = "1",
+    b = "1" + "2",
+    c = "1" + "2" + "3"
+}
+
+enum T2 {
+    a = "1",
+    b = "1" + "2"
+}
+
+enum T3 {
+    a = "1",
+    b = "1" + "2"
+}
+
+enum T4 {
+    a = "1"
+}
+
+enum T5 {
+    a = "1" + "2"
+}
+
+declare enum T6 {
+    a = "1",
+    b = "1" + "2"
+}