Roll back outer expression skipping

src/compiler/transformers/ts.ts

@@ -1923,7 +1923,7 @@ export function transformTypeScript(context: TransformationContext) {
             ),
             valueExpression,
         );
-        const outerAssignment = evaluated?.isSyntacticallyString ?
+        const outerAssignment = typeof evaluated?.value === "string" || evaluated?.isSyntacticallyString ?
             innerAssignment :
             factory.createAssignment(
                 factory.createElementAccessExpression(

src/compiler/utilities.ts

@@ -10661,7 +10661,19 @@ export function createEvaluator({ evaluateElementAccessExpression, evaluateEntit
     function evaluate(expr: Expression, location?: Declaration): EvaluatorResult {
         let isSyntacticallyString = false;
         let resolvedOtherFiles = false;
-        expr = skipOuterExpressions(expr);
+        // It's unclear when/whether we should consider skipping other kinds of outer expressions.
+        // Type assertions intentionally break evaluation when evaluating literal types, such as:
+        //     type T = `one ${"two" as any} three`; // string
+        // But it's less clear whether such an assertion should break enum member evaluation:
+        //     enum E {
+        //       A = "one" as any
+        //     }
+        // SatisfiesExpressions and non-null assertions seem to have even less reason to break
+        // emitting enum members as literals. However, these expressions also break Babel's
+        // evaluation (but not esbuild's), and the isolatedModules errors we give depend on
+        // our evaluation results, so we're currently being conservative so as to issue errors
+        // on code that might break Babel.
+        expr = skipParentheses(expr);
         switch (expr.kind) {
             case SyntaxKind.PrefixUnaryExpression:
                 const result = evaluate((expr as PrefixUnaryExpression).operand, location);
@@ -10680,8 +10692,8 @@ export function createEvaluator({ evaluateElementAccessExpression, evaluateEntit
             case SyntaxKind.BinaryExpression: {
                 const left = evaluate((expr as BinaryExpression).left, location);
                 const right = evaluate((expr as BinaryExpression).right, location);
+                isSyntacticallyString = (left.isSyntacticallyString || right.isSyntacticallyString) && (expr as BinaryExpression).operatorToken.kind === SyntaxKind.PlusToken;
                 resolvedOtherFiles = left.resolvedOtherFiles || right.resolvedOtherFiles;
-                isSyntacticallyString = left.isSyntacticallyString || right.isSyntacticallyString;
                 if (typeof left.value === "number" && typeof right.value === "number") {
                     switch ((expr as BinaryExpression).operatorToken.kind) {
                         case SyntaxKind.BarToken:
@@ -10721,6 +10733,7 @@ export function createEvaluator({ evaluateElementAccessExpression, evaluateEntit
                         resolvedOtherFiles,
                     );
                 }
+
                 break;
             }
             case SyntaxKind.StringLiteral:

tests/baselines/reference/computedEnumMemberSyntacticallyString(isolatedmodules=false).errors.txt

@@ -1,14 +1,12 @@
 computedEnumMemberSyntacticallyString.ts(4,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 computedEnumMemberSyntacticallyString.ts(5,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 computedEnumMemberSyntacticallyString.ts(6,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-computedEnumMemberSyntacticallyString.ts(7,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 computedEnumMemberSyntacticallyString.ts(8,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-computedEnumMemberSyntacticallyString.ts(10,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-computedEnumMemberSyntacticallyString.ts(11,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-computedEnumMemberSyntacticallyString.ts(14,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+computedEnumMemberSyntacticallyString.ts(9,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+computedEnumMemberSyntacticallyString.ts(12,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 
 
-==== computedEnumMemberSyntacticallyString.ts (8 errors) ====
+==== computedEnumMemberSyntacticallyString.ts (6 errors) ====
     const BAR = 2..toFixed(0);
 
     enum Foo {
@@ -21,12 +19,6 @@ computedEnumMemberSyntacticallyString.ts(14,9): error TS18033: Type 'string' is
         C = (`${BAR}`),
             ~~~~~~~~~~
 !!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-        D = (`${BAR}}`) as string,
-            ~~~~~~~~~~~~~~~~~~~~~
-!!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-        E = `${BAR}`!,
-            ~~~~~~~~~
-!!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 
         F = BAR,
             ~~~

tests/baselines/reference/computedEnumMemberSyntacticallyString(isolatedmodules=false).js

@@ -7,8 +7,6 @@ enum Foo {
     A = `${BAR}`,
     B = "2" + BAR,
     C = (`${BAR}`),
-    D = (`${BAR}}`) as string,
-    E = `${BAR}`!,
 
     F = BAR,
     G = 2 + BAR,
@@ -26,8 +24,6 @@ var Foo;
     Foo["A"] = `${BAR}`;
     Foo["B"] = "2" + BAR;
     Foo["C"] = (`${BAR}`);
-    Foo["D"] = (`${BAR}}`);
-    Foo["E"] = `${BAR}`;
     Foo[Foo["F"] = BAR] = "F";
     Foo[Foo["G"] = 2 + BAR] = "G";
     Foo["H"] = Foo.A;

tests/baselines/reference/computedEnumMemberSyntacticallyString(isolatedmodules=true).errors.txt

@@ -1,14 +1,12 @@
 computedEnumMemberSyntacticallyString.ts(4,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 computedEnumMemberSyntacticallyString.ts(5,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 computedEnumMemberSyntacticallyString.ts(6,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-computedEnumMemberSyntacticallyString.ts(7,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 computedEnumMemberSyntacticallyString.ts(8,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-computedEnumMemberSyntacticallyString.ts(10,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-computedEnumMemberSyntacticallyString.ts(11,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-computedEnumMemberSyntacticallyString.ts(14,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+computedEnumMemberSyntacticallyString.ts(9,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+computedEnumMemberSyntacticallyString.ts(12,9): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 
 
-==== computedEnumMemberSyntacticallyString.ts (8 errors) ====
+==== computedEnumMemberSyntacticallyString.ts (6 errors) ====
     const BAR = 2..toFixed(0);
 
     enum Foo {
@@ -21,12 +19,6 @@ computedEnumMemberSyntacticallyString.ts(14,9): error TS18033: Type 'string' is
         C = (`${BAR}`),
             ~~~~~~~~~~
 !!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-        D = (`${BAR}}`) as string,
-            ~~~~~~~~~~~~~~~~~~~~~
-!!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
-        E = `${BAR}`!,
-            ~~~~~~~~~
-!!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
 
         F = BAR,
             ~~~

tests/baselines/reference/computedEnumMemberSyntacticallyString(isolatedmodules=true).js

@@ -7,8 +7,6 @@ enum Foo {
     A = `${BAR}`,
     B = "2" + BAR,
     C = (`${BAR}`),
-    D = (`${BAR}}`) as string,
-    E = `${BAR}`!,
 
     F = BAR,
     G = 2 + BAR,
@@ -26,8 +24,6 @@ var Foo;
     Foo["A"] = `${BAR}`;
     Foo["B"] = "2" + BAR;
     Foo["C"] = (`${BAR}`);
-    Foo["D"] = (`${BAR}}`);
-    Foo["E"] = `${BAR}`;
     Foo[Foo["F"] = BAR] = "F";
     Foo[Foo["G"] = 2 + BAR] = "G";
     Foo["H"] = Foo.A;

tests/baselines/reference/computedEnumMemberSyntacticallyString2(isolatedmodules=false).errors.txt

@@ -0,0 +1,32 @@
+foo.ts(11,8): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+foo.ts(12,8): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+
+
+==== ./foo.ts (2 errors) ====
+    import { BAR } from './bar';
+    const LOCAL = 'LOCAL';
+
+    enum Foo {
+      A = `${BAR}`,
+
+      B = LOCAL,
+      C = B,
+      D = C + 'BAR',
+
+      E1 = (`${BAR}`) as string, // We could recognize these,
+           ~~~~~~~~~~~~~~~~~~~~
+!!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+      E2 = `${BAR}`!,             // but Babel doesn't
+           ~~~~~~~~~
+!!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+
+      F = BAR,
+      G = 2 + BAR,
+
+      H = A,
+      I = H + BAR,
+      J = H
+    }
+
+==== ./bar.ts (0 errors) ====
+    export const BAR = 'bar';

tests/baselines/reference/computedEnumMemberSyntacticallyString2(isolatedmodules=false).js

@@ -11,6 +11,9 @@ enum Foo {
   C = B,
   D = C + 'BAR',
 
+  E1 = (`${BAR}`) as string, // We could recognize these,
+  E2 = `${BAR}`!,             // but Babel doesn't
+
   F = BAR,
   G = 2 + BAR,
 
@@ -33,8 +36,10 @@ var Foo;
     Foo["B"] = "LOCAL";
     Foo["C"] = "LOCAL";
     Foo["D"] = "LOCALBAR";
-    Foo[Foo["F"] = "bar"] = "F";
-    Foo[Foo["G"] = "2bar"] = "G";
+    Foo[Foo["E1"] = (`${BAR}`)] = "E1";
+    Foo[Foo["E2"] = `${BAR}`] = "E2";
+    Foo["F"] = "bar";
+    Foo["G"] = "2bar";
     Foo["H"] = "bar";
     Foo["I"] = "barbar";
     Foo["J"] = "bar";

tests/baselines/reference/computedEnumMemberSyntacticallyString2(isolatedmodules=true).errors.txt

@@ -1,8 +1,10 @@
-foo.ts(11,7): error TS18055: 'Foo.F' has a string type, but must have syntactically recognizable string syntax when 'isolatedModules' is enabled.
-foo.ts(12,7): error TS18055: 'Foo.G' has a string type, but must have syntactically recognizable string syntax when 'isolatedModules' is enabled.
+foo.ts(11,8): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+foo.ts(12,8): error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+foo.ts(14,7): error TS18055: 'Foo.F' has a string type, but must have syntactically recognizable string syntax when 'isolatedModules' is enabled.
+foo.ts(15,7): error TS18055: 'Foo.G' has a string type, but must have syntactically recognizable string syntax when 'isolatedModules' is enabled.
 
 
-==== ./foo.ts (2 errors) ====
+==== ./foo.ts (4 errors) ====
     import { BAR } from './bar';
     const LOCAL = 'LOCAL';
 
@@ -13,6 +15,13 @@ foo.ts(12,7): error TS18055: 'Foo.G' has a string type, but must have syntactica
       C = B,
       D = C + 'BAR',
 
+      E1 = (`${BAR}`) as string, // We could recognize these,
+           ~~~~~~~~~~~~~~~~~~~~
+!!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+      E2 = `${BAR}`!,             // but Babel doesn't
+           ~~~~~~~~~
+!!! error TS18033: Type 'string' is not assignable to type 'number' as required for computed enum member values.
+
       F = BAR,
           ~~~
 !!! error TS18055: 'Foo.F' has a string type, but must have syntactically recognizable string syntax when 'isolatedModules' is enabled.

tests/baselines/reference/computedEnumMemberSyntacticallyString2(isolatedmodules=true).js

@@ -11,6 +11,9 @@ enum Foo {
   C = B,
   D = C + 'BAR',
 
+  E1 = (`${BAR}`) as string, // We could recognize these,
+  E2 = `${BAR}`!,             // but Babel doesn't
+
   F = BAR,
   G = 2 + BAR,
 
@@ -33,8 +36,10 @@ var Foo;
     Foo["B"] = "LOCAL";
     Foo["C"] = "LOCAL";
     Foo["D"] = "LOCALBAR";
-    Foo[Foo["F"] = "bar"] = "F";
-    Foo[Foo["G"] = "2bar"] = "G";
+    Foo[Foo["E1"] = (`${BAR}`)] = "E1";
+    Foo[Foo["E2"] = `${BAR}`] = "E2";
+    Foo["F"] = "bar";
+    Foo["G"] = "2bar";
     Foo["H"] = "bar";
     Foo["I"] = "barbar";
     Foo["J"] = "bar";

tests/cases/compiler/computedEnumMemberSyntacticallyString.ts

@@ -8,8 +8,6 @@ enum Foo {
     A = `${BAR}`,
     B = "2" + BAR,
     C = (`${BAR}`),
-    D = (`${BAR}}`) as string,
-    E = `${BAR}`!,
 
     F = BAR,
     G = 2 + BAR,

tests/cases/compiler/computedEnumMemberSyntacticallyString2.ts

@@ -13,6 +13,9 @@ enum Foo {
   C = B,
   D = C + 'BAR',
 
+  E1 = (`${BAR}`) as string, // We could recognize these,
+  E2 = `${BAR}`!,             // but Babel doesn't
+
   F = BAR,
   G = 2 + BAR,