Merge pull request #1522 from asger-semmle/ts-stringify-recursive-type-alias

Approved by xiemaisi

Author: semmle-qlci

javascript/extractor/lib/typescript/src/main.ts

@@ -244,7 +244,7 @@ function parseSingleFile(filename: string): {ast: ts.SourceFile, code: string} {
 
 function handleOpenProjectCommand(command: OpenProjectCommand) {
     let tsConfigFilename = String(command.tsConfig);
-    let tsConfig = ts.readConfigFile(tsConfigFilename, ts.sys.readFile)
+    let tsConfig = ts.readConfigFile(tsConfigFilename, ts.sys.readFile);
     let basePath = pathlib.dirname(tsConfigFilename);
 
     let parseConfigHost: ts.ParseConfigHost = {

javascript/extractor/lib/typescript/src/type_table.ts

@@ -436,7 +436,10 @@ export class TypeTable {
     let toStringValue: string;
     // Some types can't be stringified. Just discard the type if we can't stringify it.
     try {
-      toStringValue = this.typeChecker.typeToString(type);
+      toStringValue = this.typeChecker.typeToString(
+            type,
+            undefined,
+            ts.TypeFormatFlags.UseAliasDefinedOutsideCurrentScope);
     } catch (e) {
       console.warn("Recovered from a compiler crash while stringifying a type. Discarding the type.");
       console.warn(e.stack);
@@ -454,7 +457,11 @@ export class TypeTable {
     // Some types can't be stringified. Just discard the type if we can't stringify it.
     try {
       toStringValue =
-          this.typeChecker.signatureToString(signature, signature.declaration, ts.TypeFormatFlags.None, kind);
+          this.typeChecker.signatureToString(
+              signature,
+              signature.declaration,
+              ts.TypeFormatFlags.UseAliasDefinedOutsideCurrentScope,
+              kind);
     } catch (e) {
       console.warn("Recovered from a compiler crash while stringifying a signature. Discarding the signature.");
       console.warn(e.stack);

javascript/ql/test/library-tests/TypeScript/ExternalTypes/UniqueSymbols.expected

@@ -1 +1 @@
-| unique symbol | esmodule | externalSymbol |
+| typeof externalSymbol | esmodule | externalSymbol |

javascript/ql/test/library-tests/TypeScript/RegressionTests/RecursiveTypeAlias/Test.expected

@@ -0,0 +1,2 @@
+| test.ts:3:1:7:6 | type Di ... \\n    T; | Disjunction<T> |
+| test.ts:9:8:9:65 | type Tr ... n<T>>>; | Disjunction<Disjunction<Disjunction<T>>> |

javascript/ql/test/library-tests/TypeScript/RegressionTests/RecursiveTypeAlias/Test.ql

@@ -0,0 +1,4 @@
+import javascript
+
+from TypeAliasDeclaration decl
+select decl, decl.getDefinition().getType()

javascript/ql/test/library-tests/TypeScript/RegressionTests/RecursiveTypeAlias/test.ts

@@ -0,0 +1,9 @@
+import { ArrayBox, Box } from 'somewhere';
+
+type Disjunction<T> =
+    T extends ArrayBox<infer U1> ? U1[] :
+    T extends Box<infer U2> ? U2 :
+    T extends ({[P in keyof T]: T[P]} & {p: any}) ? {[P in Exclude<keyof T, 'p'>]: Disjunction<T[P]>} :
+    T;
+
+export type Triple<T> = Disjunction<Disjunction<Disjunction<T>>>;

javascript/ql/test/library-tests/TypeScript/RegressionTests/RecursiveTypeAlias/tsconfig.json

@@ -0,0 +1 @@
+{}

javascript/ql/test/library-tests/TypeScript/Types/GetExprType.expected

@@ -69,7 +69,7 @@
 | tst.ts:28:22:28:25 | null | null |
 | tst.ts:29:5:29:13 | neverType | () => never |
 | tst.ts:30:5:30:14 | symbolType | symbol |
-| tst.ts:31:7:31:22 | uniqueSymbolType | unique symbol |
+| tst.ts:31:7:31:22 | uniqueSymbolType | typeof uniqueSymbolType |
 | tst.ts:31:41:31:44 | null | null |
 | tst.ts:32:5:32:14 | objectType | object |
 | tst.ts:33:5:33:16 | intersection | string & { x: string; } |

javascript/ql/test/library-tests/TypeScript/Types/GetTypeExprType.expected

@@ -40,7 +40,7 @@
 | tst.ts:29:16:29:26 | () => never | () => never |
 | tst.ts:29:22:29:26 | never | never |
 | tst.ts:30:17:30:22 | symbol | symbol |
-| tst.ts:31:25:31:37 | unique symbol | unique symbol |
+| tst.ts:31:25:31:37 | unique symbol | typeof uniqueSymbolType |
 | tst.ts:32:17:32:22 | object | object |
 | tst.ts:33:19:33:24 | string | string |
 | tst.ts:33:19:33:38 | string & {x: string} | string & { x: string; } |