Add used-before-declaration errors for class refs inside computed names

src/compiler/checker.ts

@@ -1126,6 +1126,10 @@ namespace ts {
                     // still might be illegal if usage is in the initializer of the variable declaration (eg var a = a)
                     return !isImmediatelyUsedInInitializerOfBlockScopedVariable(declaration as VariableDeclaration, usage);
                 }
+                else if (isClassDeclaration(declaration)) {
+                    // still might be illegal if the usage is within a computed property name in the class (eg class A { static p = "a"; [A.p]() {} })
+                    return !findAncestor(usage, n => isComputedPropertyName(n) && n.parent.parent === declaration);
+                }
                 return true;
             }
 

tests/baselines/reference/classDeclarationShouldBeOutOfScopeInComputedNames.errors.txt

@@ -0,0 +1,25 @@
+tests/cases/compiler/classDeclarationShouldBeOutOfScopeInComputedNames.ts(5,22): error TS2449: Class 'A' used before its declaration.
+tests/cases/compiler/classDeclarationShouldBeOutOfScopeInComputedNames.ts(6,13): error TS2449: Class 'A' used before its declaration.
+tests/cases/compiler/classDeclarationShouldBeOutOfScopeInComputedNames.ts(7,6): error TS2449: Class 'A' used before its declaration.
+tests/cases/compiler/classDeclarationShouldBeOutOfScopeInComputedNames.ts(8,6): error TS2449: Class 'A' used before its declaration.
+
+
+==== tests/cases/compiler/classDeclarationShouldBeOutOfScopeInComputedNames.ts (4 errors) ====
+    class A {
+        static readonly p1 = Symbol();
+        static readonly p2 = Symbol();
+        // All of the below should be out of scope or TDZ - `A` has not finished being constructed as they are executed
+        static readonly [A.p1] = 0;
+                         ~
+!!! error TS2449: Class 'A' used before its declaration.
+        static [A.p2]() { return 0 };
+                ~
+!!! error TS2449: Class 'A' used before its declaration.
+        [A.p1]() { }
+         ~
+!!! error TS2449: Class 'A' used before its declaration.
+        [A.p2] = 0
+         ~
+!!! error TS2449: Class 'A' used before its declaration.
+    }
+

tests/baselines/reference/classDeclarationShouldBeOutOfScopeInComputedNames.js

@@ -0,0 +1,28 @@
+//// [classDeclarationShouldBeOutOfScopeInComputedNames.ts]
+class A {
+    static readonly p1 = Symbol();
+    static readonly p2 = Symbol();
+    // All of the below should be out of scope or TDZ - `A` has not finished being constructed as they are executed
+    static readonly [A.p1] = 0;
+    static [A.p2]() { return 0 };
+    [A.p1]() { }
+    [A.p2] = 0
+}
+
+
+//// [classDeclarationShouldBeOutOfScopeInComputedNames.js]
+var A = /** @class */ (function () {
+    function A() {
+        this[_a] = 0;
+    }
+    A[(_b = A.p1, A.p2)] = function () { return 0; };
+    ;
+    A.prototype[A.p1] = function () { };
+    _a = A.p2;
+    A.p1 = Symbol();
+    A.p2 = Symbol();
+    // All of the below should be out of scope or TDZ - `A` has not finished being constructed as they are executed
+    A[_b] = 0;
+    return A;
+    var _b, _a;
+}());

tests/baselines/reference/classDeclarationShouldBeOutOfScopeInComputedNames.symbols

@@ -0,0 +1,38 @@
+=== tests/cases/compiler/classDeclarationShouldBeOutOfScopeInComputedNames.ts ===
+class A {
+>A : Symbol(A, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 0))
+
+    static readonly p1 = Symbol();
+>p1 : Symbol(A.p1, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 9))
+>Symbol : Symbol(Symbol, Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --))
+
+    static readonly p2 = Symbol();
+>p2 : Symbol(A.p2, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 1, 34))
+>Symbol : Symbol(Symbol, Decl(lib.es2015.symbol.wellknown.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --), Decl(lib.es2015.symbol.d.ts, --, --))
+
+    // All of the below should be out of scope or TDZ - `A` has not finished being constructed as they are executed
+    static readonly [A.p1] = 0;
+>[A.p1] : Symbol(A[A.p1], Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 2, 34))
+>A.p1 : Symbol(A.p1, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 9))
+>A : Symbol(A, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 0))
+>p1 : Symbol(A.p1, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 9))
+
+    static [A.p2]() { return 0 };
+>[A.p2] : Symbol(A[A.p2], Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 4, 31))
+>A.p2 : Symbol(A.p2, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 1, 34))
+>A : Symbol(A, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 0))
+>p2 : Symbol(A.p2, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 1, 34))
+
+    [A.p1]() { }
+>[A.p1] : Symbol(A[A.p1], Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 5, 33))
+>A.p1 : Symbol(A.p1, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 9))
+>A : Symbol(A, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 0))
+>p1 : Symbol(A.p1, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 9))
+
+    [A.p2] = 0
+>[A.p2] : Symbol(A[A.p2], Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 6, 16))
+>A.p2 : Symbol(A.p2, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 1, 34))
+>A : Symbol(A, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 0, 0))
+>p2 : Symbol(A.p2, Decl(classDeclarationShouldBeOutOfScopeInComputedNames.ts, 1, 34))
+}
+

tests/baselines/reference/classDeclarationShouldBeOutOfScopeInComputedNames.types

@@ -0,0 +1,43 @@
+=== tests/cases/compiler/classDeclarationShouldBeOutOfScopeInComputedNames.ts ===
+class A {
+>A : A
+
+    static readonly p1 = Symbol();
+>p1 : unique symbol
+>Symbol() : unique symbol
+>Symbol : SymbolConstructor
+
+    static readonly p2 = Symbol();
+>p2 : unique symbol
+>Symbol() : unique symbol
+>Symbol : SymbolConstructor
+
+    // All of the below should be out of scope or TDZ - `A` has not finished being constructed as they are executed
+    static readonly [A.p1] = 0;
+>[A.p1] : 0
+>A.p1 : unique symbol
+>A : typeof A
+>p1 : unique symbol
+>0 : 0
+
+    static [A.p2]() { return 0 };
+>[A.p2] : () => number
+>A.p2 : unique symbol
+>A : typeof A
+>p2 : unique symbol
+>0 : 0
+
+    [A.p1]() { }
+>[A.p1] : () => void
+>A.p1 : unique symbol
+>A : typeof A
+>p1 : unique symbol
+
+    [A.p2] = 0
+>[A.p2] : number
+>A.p2 : unique symbol
+>A : typeof A
+>p2 : unique symbol
+>0 : 0
+}
+

tests/baselines/reference/computedPropertyNamesWithStaticProperty.errors.txt

@@ -0,0 +1,22 @@
+tests/cases/conformance/es6/computedProperties/computedPropertyNamesWithStaticProperty.ts(3,10): error TS2449: Class 'C' used before its declaration.
+tests/cases/conformance/es6/computedProperties/computedPropertyNamesWithStaticProperty.ts(6,10): error TS2449: Class 'C' used before its declaration.
+tests/cases/conformance/es6/computedProperties/computedPropertyNamesWithStaticProperty.ts(9,6): error TS2449: Class 'C' used before its declaration.
+
+
+==== tests/cases/conformance/es6/computedProperties/computedPropertyNamesWithStaticProperty.ts (3 errors) ====
+    class C {
+        static staticProp = 10;
+        get [C.staticProp]() {
+             ~
+!!! error TS2449: Class 'C' used before its declaration.
+            return "hello";
+        }
+        set [C.staticProp](x: string) {
+             ~
+!!! error TS2449: Class 'C' used before its declaration.
+            var y = x;
+        }
+        [C.staticProp]() { }
+         ~
+!!! error TS2449: Class 'C' used before its declaration.
+    }

tests/cases/compiler/classDeclarationShouldBeOutOfScopeInComputedNames.ts

@@ -0,0 +1,10 @@
+// @lib: es6
+class A {
+    static readonly p1 = Symbol();
+    static readonly p2 = Symbol();
+    // All of the below should be out of scope or TDZ - `A` has not finished being constructed as they are executed
+    static readonly [A.p1] = 0;
+    static [A.p2]() { return 0 };
+    [A.p1]() { }
+    [A.p2] = 0
+}