allow string concat in enum member declaration

Author: 王文璐

src/compiler/checker.ts

@@ -22962,9 +22962,16 @@ namespace ts {
                                 case SyntaxKind.AsteriskAsteriskToken: return left ** right;
                             }
                         }
+                        if (typeof left === "string" && typeof right === "string") {
+                            switch ((<BinaryExpression>expr).operatorToken.kind) {
+                                case SyntaxKind.PlusToken: return left + right;
+                            }
+                        }
                         break;
                     case SyntaxKind.StringLiteral:
                         return (<StringLiteral>expr).text;
+                    case SyntaxKind.NoSubstitutionTemplateLiteral:
+                        return (<NoSubstitutionTemplateLiteral>expr).text;
                     case SyntaxKind.NumericLiteral:
                         checkGrammarNumericLiteral(<NumericLiteral>expr);
                         return +(<NumericLiteral>expr).text;

tests/baselines/reference/enumConstantMemberWithString.errors.txt

@@ -0,0 +1,30 @@
+tests/cases/conformance/enums/enumConstantMemberWithString.ts(5,9): error TS2362: The left-hand side of an arithmetic operation must be of type 'any', 'number' or an enum type.
+tests/cases/conformance/enums/enumConstantMemberWithString.ts(5,15): error TS2363: The right-hand side of an arithmetic operation must be of type 'any', 'number' or an enum type.
+tests/cases/conformance/enums/enumConstantMemberWithString.ts(6,9): error TS2322: Type 'string' is not assignable to type 'T2'.
+tests/cases/conformance/enums/enumConstantMemberWithString.ts(7,9): error TS2322: Type 'string' is not assignable to type 'T2'.
+
+
+==== tests/cases/conformance/enums/enumConstantMemberWithString.ts (4 errors) ====
+    enum T2 {
+        a = "1" + "2",
+        b = `a`,
+        c = "a" + `b`,
+        d = "a" - "a",
+            ~~~
+!!! error TS2362: The left-hand side of an arithmetic operation must be of type 'any', 'number' or an enum type.
+                  ~~~
+!!! error TS2363: The right-hand side of an arithmetic operation must be of type 'any', 'number' or an enum type.
+        e = "a" + 1,
+            ~~~~~~~
+!!! error TS2322: Type 'string' is not assignable to type 'T2'.
+        f = `a${1}`
+            ~~~~~~~
+!!! error TS2322: Type 'string' is not assignable to type 'T2'.
+    }
+    
+    declare enum T3 {
+        a = "1" + "2",
+        b = `a`,
+        c = "a" + `b`
+    }
+    

tests/baselines/reference/enumConstantMemberWithString.js

@@ -0,0 +1,27 @@
+//// [enumConstantMemberWithString.ts]
+enum T2 {
+    a = "1" + "2",
+    b = `a`,
+    c = "a" + `b`,
+    d = "a" - "a",
+    e = "a" + 1,
+    f = `a${1}`
+}
+
+declare enum T3 {
+    a = "1" + "2",
+    b = `a`,
+    c = "a" + `b`
+}
+
+
+//// [enumConstantMemberWithString.js]
+var T2;
+(function (T2) {
+    T2["a"] = "12";
+    T2["b"] = "a";
+    T2["c"] = "ab";
+    T2[T2["d"] = "a" - "a"] = "d";
+    T2[T2["e"] = "a" + 1] = "e";
+    T2[T2["f"] = "a" + 1] = "f";
+})(T2 || (T2 = {}));

tests/baselines/reference/enumConstantMemberWithString.symbols

@@ -0,0 +1,36 @@
+=== tests/cases/conformance/enums/enumConstantMemberWithString.ts ===
+enum T2 {
+>T2 : Symbol(T2, Decl(enumConstantMemberWithString.ts, 0, 0))
+
+    a = "1" + "2",
+>a : Symbol(T2.a, Decl(enumConstantMemberWithString.ts, 0, 9))
+
+    b = `a`,
+>b : Symbol(T2.b, Decl(enumConstantMemberWithString.ts, 1, 18))
+
+    c = "a" + `b`,
+>c : Symbol(T2.c, Decl(enumConstantMemberWithString.ts, 2, 12))
+
+    d = "a" - "a",
+>d : Symbol(T2.d, Decl(enumConstantMemberWithString.ts, 3, 18))
+
+    e = "a" + 1,
+>e : Symbol(T2.e, Decl(enumConstantMemberWithString.ts, 4, 18))
+
+    f = `a${1}`
+>f : Symbol(T2.f, Decl(enumConstantMemberWithString.ts, 5, 16))
+}
+
+declare enum T3 {
+>T3 : Symbol(T3, Decl(enumConstantMemberWithString.ts, 7, 1))
+
+    a = "1" + "2",
+>a : Symbol(T3.a, Decl(enumConstantMemberWithString.ts, 9, 17))
+
+    b = `a`,
+>b : Symbol(T3.b, Decl(enumConstantMemberWithString.ts, 10, 18))
+
+    c = "a" + `b`
+>c : Symbol(T3.c, Decl(enumConstantMemberWithString.ts, 11, 12))
+}
+

tests/baselines/reference/enumConstantMemberWithString.types

@@ -0,0 +1,58 @@
+=== tests/cases/conformance/enums/enumConstantMemberWithString.ts ===
+enum T2 {
+>T2 : T2
+
+    a = "1" + "2",
+>a : T2
+>"1" + "2" : string
+>"1" : "1"
+>"2" : "2"
+
+    b = `a`,
+>b : T2
+>`a` : "a"
+
+    c = "a" + `b`,
+>c : T2
+>"a" + `b` : string
+>"a" : "a"
+>`b` : "b"
+
+    d = "a" - "a",
+>d : T2
+>"a" - "a" : number
+>"a" : "a"
+>"a" : "a"
+
+    e = "a" + 1,
+>e : T2
+>"a" + 1 : string
+>"a" : "a"
+>1 : 1
+
+    f = `a${1}`
+>f : T2
+>`a${1}` : string
+>1 : 1
+}
+
+declare enum T3 {
+>T3 : T3
+
+    a = "1" + "2",
+>a : T3
+>"1" + "2" : string
+>"1" : "1"
+>"2" : "2"
+
+    b = `a`,
+>b : T3
+>`a` : "a"
+
+    c = "a" + `b`
+>c : T3
+>"a" + `b` : string
+>"a" : "a"
+>`b` : "b"
+}
+

tests/cases/conformance/enums/enumConstantMemberWithString.ts

@@ -0,0 +1,14 @@
+enum T2 {
+    a = "1" + "2",
+    b = `a`,
+    c = "a" + `b`,
+    d = "a" - "a",
+    e = "a" + 1,
+    f = `a${1}`
+}
+
+declare enum T3 {
+    a = "1" + "2",
+    b = `a`,
+    c = "a" + `b`
+}