From b93892a6f318ee9a78c2e7100e0c5382e9095b27 Mon Sep 17 00:00:00 2001
From: Nathan Shively-Sanders <293473+sandersn@users.noreply.github.com>
Date: Wed, 20 Oct 2021 16:46:49 -0700
Subject: [PATCH] Computed property names are const contexts

By analogy with the existing rule that element access argument
expressions are a const context.

Fixes #45798
---
 src/compiler/checker.ts                       |  1 +
 .../constContextTemplateLiteral.errors.txt    | 27 +++++++++++
 .../reference/constContextTemplateLiteral.js  | 31 ++++++++++++
 .../constContextTemplateLiteral.symbols       | 37 +++++++++++++++
 .../constContextTemplateLiteral.types         | 47 +++++++++++++++++++
 .../literals/constContextTemplateLiteral.ts   | 13 +++++
 6 files changed, 156 insertions(+)
 create mode 100644 tests/baselines/reference/constContextTemplateLiteral.errors.txt
 create mode 100644 tests/baselines/reference/constContextTemplateLiteral.js
 create mode 100644 tests/baselines/reference/constContextTemplateLiteral.symbols
 create mode 100644 tests/baselines/reference/constContextTemplateLiteral.types
 create mode 100644 tests/cases/conformance/expressions/literals/constContextTemplateLiteral.ts

diff --git a/src/compiler/checker.ts b/src/compiler/checker.ts
index d149b04428..9925478b31 100644
--- a/src/compiler/checker.ts
+++ b/src/compiler/checker.ts
@@ -33488,6 +33488,7 @@ namespace ts {
             const parent = node.parent;
             return isAssertionExpression(parent) && isConstTypeReference(parent.type) ||
                 isJSDocTypeAssertion(parent) && isConstTypeReference(getJSDocTypeAssertionType(parent)) ||
+                isComputedPropertyName(parent) ||
                 (isParenthesizedExpression(parent) || isArrayLiteralExpression(parent) || isSpreadElement(parent)) && isConstContext(parent) ||
                 (isPropertyAssignment(parent) || isShorthandPropertyAssignment(parent) || isTemplateSpan(parent)) && isConstContext(parent.parent);
         }
diff --git a/tests/baselines/reference/constContextTemplateLiteral.errors.txt b/tests/baselines/reference/constContextTemplateLiteral.errors.txt
new file mode 100644
index 0000000000..2f084fda02
--- /dev/null
+++ b/tests/baselines/reference/constContextTemplateLiteral.errors.txt
@@ -0,0 +1,27 @@
+tests/cases/conformance/expressions/literals/constContextTemplateLiteral.ts(10,24): error TS2418: Type of computed property's value is '{ b: string; }', which is not assignable to type '{ a: any; }'.
+  Object literal may only specify known properties, and 'b' does not exist in type '{ a: any; }'.
+tests/cases/conformance/expressions/literals/constContextTemplateLiteral.ts(11,33): error TS2418: Type of computed property's value is '{ b: string; }', which is not assignable to type '{ a: any; }'.
+  Object literal may only specify known properties, and 'b' does not exist in type '{ a: any; }'.
+
+
+==== tests/cases/conformance/expressions/literals/constContextTemplateLiteral.ts (2 errors) ====
+    interface Person {
+        id: number;
+        name: string;
+    }
+    
+    declare function key(): `person-${number}`
+    /* This only happens if index type is a template literal type */
+    const persons: Record<`person-${Person["id"]}`, { a: any }> = {
+        ...{},
+        [`person-${1}`]: { b: "something" }, // ok, error
+                           ~~~~~~~~~~~~~~
+!!! error TS2418: Type of computed property's value is '{ b: string; }', which is not assignable to type '{ a: any; }'.
+!!! error TS2418:   Object literal may only specify known properties, and 'b' does not exist in type '{ a: any; }'.
+        [`person-${1}` as const]: { b: "something" }, // ok, error
+                                    ~~~~~~~~~~~~~~
+!!! error TS2418: Type of computed property's value is '{ b: string; }', which is not assignable to type '{ a: any; }'.
+!!! error TS2418:   Object literal may only specify known properties, and 'b' does not exist in type '{ a: any; }'.
+        [key()]: { b: "something" }, // still no error
+    }
+    
\ No newline at end of file
diff --git a/tests/baselines/reference/constContextTemplateLiteral.js b/tests/baselines/reference/constContextTemplateLiteral.js
new file mode 100644
index 0000000000..10f4d01362
--- /dev/null
+++ b/tests/baselines/reference/constContextTemplateLiteral.js
@@ -0,0 +1,31 @@
+//// [constContextTemplateLiteral.ts]
+interface Person {
+    id: number;
+    name: string;
+}
+
+declare function key(): `person-${number}`
+/* This only happens if index type is a template literal type */
+const persons: Record<`person-${Person["id"]}`, { a: any }> = {
+    ...{},
+    [`person-${1}`]: { b: "something" }, // ok, error
+    [`person-${1}` as const]: { b: "something" }, // ok, error
+    [key()]: { b: "something" }, // still no error
+}
+
+
+//// [constContextTemplateLiteral.js]
+var __assign = (this && this.__assign) || function () {
+    __assign = Object.assign || function(t) {
+        for (var s, i = 1, n = arguments.length; i < n; i++) {
+            s = arguments[i];
+            for (var p in s) if (Object.prototype.hasOwnProperty.call(s, p))
+                t[p] = s[p];
+        }
+        return t;
+    };
+    return __assign.apply(this, arguments);
+};
+var _a;
+/* This only happens if index type is a template literal type */
+var persons = __assign({}, (_a = {}, _a["person-".concat(1)] = { b: "something" }, _a["person-".concat(1)] = { b: "something" }, _a[key()] = { b: "something" }, _a));
diff --git a/tests/baselines/reference/constContextTemplateLiteral.symbols b/tests/baselines/reference/constContextTemplateLiteral.symbols
new file mode 100644
index 0000000000..2d31f131f2
--- /dev/null
+++ b/tests/baselines/reference/constContextTemplateLiteral.symbols
@@ -0,0 +1,37 @@
+=== tests/cases/conformance/expressions/literals/constContextTemplateLiteral.ts ===
+interface Person {
+>Person : Symbol(Person, Decl(constContextTemplateLiteral.ts, 0, 0))
+
+    id: number;
+>id : Symbol(Person.id, Decl(constContextTemplateLiteral.ts, 0, 18))
+
+    name: string;
+>name : Symbol(Person.name, Decl(constContextTemplateLiteral.ts, 1, 15))
+}
+
+declare function key(): `person-${number}`
+>key : Symbol(key, Decl(constContextTemplateLiteral.ts, 3, 1))
+
+/* This only happens if index type is a template literal type */
+const persons: Record<`person-${Person["id"]}`, { a: any }> = {
+>persons : Symbol(persons, Decl(constContextTemplateLiteral.ts, 7, 5))
+>Record : Symbol(Record, Decl(lib.es5.d.ts, --, --))
+>Person : Symbol(Person, Decl(constContextTemplateLiteral.ts, 0, 0))
+>a : Symbol(a, Decl(constContextTemplateLiteral.ts, 7, 49))
+
+    ...{},
+    [`person-${1}`]: { b: "something" }, // ok, error
+>[`person-${1}`] : Symbol([`person-${1}`], Decl(constContextTemplateLiteral.ts, 8, 10))
+>b : Symbol(b, Decl(constContextTemplateLiteral.ts, 9, 22))
+
+    [`person-${1}` as const]: { b: "something" }, // ok, error
+>[`person-${1}` as const] : Symbol([`person-${1}` as const], Decl(constContextTemplateLiteral.ts, 9, 40))
+>const : Symbol(const)
+>b : Symbol(b, Decl(constContextTemplateLiteral.ts, 10, 31))
+
+    [key()]: { b: "something" }, // still no error
+>[key()] : Symbol([key()], Decl(constContextTemplateLiteral.ts, 10, 49))
+>key : Symbol(key, Decl(constContextTemplateLiteral.ts, 3, 1))
+>b : Symbol(b, Decl(constContextTemplateLiteral.ts, 11, 14))
+}
+
diff --git a/tests/baselines/reference/constContextTemplateLiteral.types b/tests/baselines/reference/constContextTemplateLiteral.types
new file mode 100644
index 0000000000..99fcfb91c1
--- /dev/null
+++ b/tests/baselines/reference/constContextTemplateLiteral.types
@@ -0,0 +1,47 @@
+=== tests/cases/conformance/expressions/literals/constContextTemplateLiteral.ts ===
+interface Person {
+    id: number;
+>id : number
+
+    name: string;
+>name : string
+}
+
+declare function key(): `person-${number}`
+>key : () => `person-${number}`
+
+/* This only happens if index type is a template literal type */
+const persons: Record<`person-${Person["id"]}`, { a: any }> = {
+>persons : Record<`person-${number}`, { a: any; }>
+>a : any
+>{    ...{},    [`person-${1}`]: { b: "something" }, // ok, error    [`person-${1}` as const]: { b: "something" }, // ok, error    [key()]: { b: "something" }, // still no error} : { "person-1": { b: string; }; }
+
+    ...{},
+>{} : {}
+
+    [`person-${1}`]: { b: "something" }, // ok, error
+>[`person-${1}`] : { b: string; }
+>`person-${1}` : "person-1"
+>1 : 1
+>{ b: "something" } : { b: string; }
+>b : string
+>"something" : "something"
+
+    [`person-${1}` as const]: { b: "something" }, // ok, error
+>[`person-${1}` as const] : { b: string; }
+>`person-${1}` as const : "person-1"
+>`person-${1}` : "person-1"
+>1 : 1
+>{ b: "something" } : { b: string; }
+>b : string
+>"something" : "something"
+
+    [key()]: { b: "something" }, // still no error
+>[key()] : { b: string; }
+>key() : `person-${number}`
+>key : () => `person-${number}`
+>{ b: "something" } : { b: string; }
+>b : string
+>"something" : "something"
+}
+
diff --git a/tests/cases/conformance/expressions/literals/constContextTemplateLiteral.ts b/tests/cases/conformance/expressions/literals/constContextTemplateLiteral.ts
new file mode 100644
index 0000000000..c40bc2bbad
--- /dev/null
+++ b/tests/cases/conformance/expressions/literals/constContextTemplateLiteral.ts
@@ -0,0 +1,13 @@
+interface Person {
+    id: number;
+    name: string;
+}
+
+declare function key(): `person-${number}`
+/* This only happens if index type is a template literal type */
+const persons: Record<`person-${Person["id"]}`, { a: any }> = {
+    ...{},
+    [`person-${1}`]: { b: "something" }, // ok, error
+    [`person-${1}` as const]: { b: "something" }, // ok, error
+    [key()]: { b: "something" }, // still no error
+}