v3.21.0

CHANGELOG.md

@@ -1,3 +1,10 @@
+# 3.21.0
+
+**Features:**
+
+* added `getWellKnownSymbolPropertyOfType` to reliably get symbol named properties due to changes in typescript@4.3
+* `getPropertyNameOfWellKnownSymbol` is now deprecated
+
 # 3.20.0
 
 **Features:**

package.json

@@ -1,6 +1,6 @@
 {
   "name": "tsutils",
-  "version": "3.20.0",
+  "version": "3.21.0",
   "description": "utilities for working with typescript's AST",
   "scripts": {
     "precompile": "rimraf \"{,util,typeguard,test{,/rules}/*.{js,d.ts,js.map}\"",

util/type.ts

@@ -30,6 +30,8 @@ import {
     isShorthandPropertyAssignment,
     isEnumMember,
     isClassLikeDeclaration,
+    isInterfaceDeclaration,
+    isSourceFile,
 } from '../typeguard/node';
 
 export function isEmptyObjectType(type: ts.Type): type is ts.ObjectType {
@@ -205,6 +207,29 @@ export function getPropertyOfType(type: ts.Type, name: ts.__String) {
     return type.getProperties().find((s) => s.escapedName === name);
 }
 
+export function getWellKnownSymbolPropertyOfType(type: ts.Type, wellKnownSymbolName: string, checker: ts.TypeChecker) {
+    const prefix = '__@' + wellKnownSymbolName;
+    for (const prop of type.getProperties()) {
+        if (!prop.name.startsWith(prefix))
+            continue;
+        const globalSymbol = checker.getApparentType(
+            checker.getTypeAtLocation((<ts.ComputedPropertyName>(<ts.NamedDeclaration>prop.valueDeclaration).name).expression),
+        ).symbol;
+        if (prop.escapedName === getPropertyNameOfWellKnownSymbol(checker, globalSymbol, wellKnownSymbolName))
+            return prop;
+    }
+    return;
+}
+
+function getPropertyNameOfWellKnownSymbol(checker: ts.TypeChecker, symbolConstructor: ts.Symbol | undefined, symbolName: string) {
+    const knownSymbol = symbolConstructor &&
+        checker.getTypeOfSymbolAtLocation(symbolConstructor, symbolConstructor.valueDeclaration).getProperty(symbolName);
+    const knownSymbolType = knownSymbol && checker.getTypeOfSymbolAtLocation(knownSymbol, knownSymbol.valueDeclaration);
+    if (knownSymbolType && isUniqueESSymbolType(knownSymbolType))
+        return knownSymbolType.escapedName;
+    return <ts.__String>('__@' + symbolName);
+}
+
 /** Determines if writing to a certain property of a given type is allowed. */
 export function isPropertyReadonlyInType(type: ts.Type, name: ts.__String, checker: ts.TypeChecker): boolean {
     let seenProperty = false;
@@ -285,11 +310,26 @@ export function getPropertyNameFromType(type: ts.Type): PropertyName | undefined
     }
     if (isUniqueESSymbolType(type))
         return {
-            displayName: `[${type.symbol ? type.symbol.name : (<string>type.escapedName).replace(/^__@|@\d+$/g, '')}]`,
+            displayName: `[${type.symbol
+                ? `${isKnownSymbol(type.symbol) ? 'Symbol.' : ''}${type.symbol.name}`
+                : (<string>type.escapedName).replace(/^__@|@\d+$/g, '')
+            }]`,
             symbolName: type.escapedName,
         };
 }
 
+function isKnownSymbol(symbol: ts.Symbol): boolean {
+    return isSymbolFlagSet(symbol, ts.SymbolFlags.Property) &&
+        symbol.valueDeclaration !== undefined &&
+        isInterfaceDeclaration(symbol.valueDeclaration.parent) &&
+        symbol.valueDeclaration.parent.name.text === 'SymbolConstructor' &&
+        isGlobalDeclaration(symbol.valueDeclaration.parent);
+}
+
+function isGlobalDeclaration(node: ts.DeclarationStatement): boolean {
+    return isNodeFlagSet(node.parent!, ts.NodeFlags.GlobalAugmentation) || isSourceFile(node.parent) && !ts.isExternalModule(node.parent);
+}
+
 export function getSymbolOfClassLikeDeclaration(node: ts.ClassLikeDeclaration, checker: ts.TypeChecker) {
     return checker.getSymbolAtLocation(node.name ?? getChildOfKind(node, ts.SyntaxKind.ClassKeyword)!)!;
 }

util/util.ts

@@ -1647,13 +1647,16 @@ export interface PropertyName {
     symbolName: ts.__String;
 }
 
+/** @deprecated typescript 4.3 removed the concept of literal well known symbols. Use `getPropertyNameFromType` instead. */
 export function getPropertyNameOfWellKnownSymbol(node: WellKnownSymbolLiteral): PropertyName {
     return {
         displayName: `[Symbol.${node.name.text}]`,
         symbolName: <ts.__String>('__@' + node.name.text),
     };
 }
 
+const isTsBefore43 = (([major, minor]) => major < '4' || major === '4' && minor < '3')(ts.versionMajorMinor.split('.'));
+
 export interface LateBoundPropertyNames {
     /** Whether all constituents are literal names. */
     known: boolean;
@@ -1667,8 +1670,8 @@ export function getLateBoundPropertyNames(node: ts.Expression, checker: ts.TypeC
     };
 
     node = unwrapParentheses(node);
-    if (isWellKnownSymbolLiterally(node)) {
-        result.names.push(getPropertyNameOfWellKnownSymbol(node));
+    if (isTsBefore43 && isWellKnownSymbolLiterally(node)) {
+        result.names.push(getPropertyNameOfWellKnownSymbol(node)); // wotan-disable-line no-unstable-api-use
     } else {
         const type = checker.getTypeAtLocation(node);
         for (const key of unionTypeParts(checker.getBaseConstraintOfType(type) || type)) {
@@ -1700,8 +1703,8 @@ export function getSingleLateBoundPropertyNameOfPropertyName(node: ts.PropertyNa
     if (node.kind === ts.SyntaxKind.PrivateIdentifier)
         return {displayName: node.text, symbolName: checker.getSymbolAtLocation(node)!.escapedName};
     const {expression} = <ts.ComputedPropertyName>node;
-    return isWellKnownSymbolLiterally(expression)
-        ? getPropertyNameOfWellKnownSymbol(expression)
+    return isTsBefore43 && isWellKnownSymbolLiterally(expression)
+        ? getPropertyNameOfWellKnownSymbol(expression) // wotan-disable-line no-unstable-api-use
         : getPropertyNameFromType(checker.getTypeAtLocation(expression));
 }