TS: Resolve imports using TypeScript symbols

javascript/ql/src/semmle/javascript/Modules.qll

@@ -148,6 +148,16 @@ abstract class Import extends ASTNode {
       )
   }
 
+  /**
+   * Gets the imported module, as determined by the TypeScript compiler, if any.
+   */
+  private Module resolveFromTypeScriptSymbol() {
+    exists(CanonicalName symbol |
+      ast_node_symbol(this, symbol) and
+      ast_node_symbol(result, symbol)
+    )
+  }
+
   /**
    * Gets the module this import refers to.
    *
@@ -162,7 +172,8 @@ abstract class Import extends ASTNode {
     else (
       result = resolveAsProvidedModule() or
       result = resolveImportedPath() or
-      result = resolveFromTypeRoot()
+      result = resolveFromTypeRoot() or
+      result = resolveFromTypeScriptSymbol()
     )
   }
 

javascript/ql/src/semmlecode.javascript.dbscheme

@@ -688,7 +688,7 @@ case @symbol.kind of
 ;
 
 @type_with_symbol = @typereference | @typevariabletype | @typeoftype | @uniquesymboltype;
-@ast_node_with_symbol = @typedefinition | @namespacedefinition | @toplevel | @typeaccess | @namespaceaccess | @vardecl | @function | @invokeexpr;
+@ast_node_with_symbol = @typedefinition | @namespacedefinition | @toplevel | @typeaccess | @namespaceaccess | @vardecl | @function | @invokeexpr | @importdeclaration | @externalmodulereference;
 
 ast_node_symbol(
   unique int node: @ast_node_with_symbol ref,

javascript/ql/test/library-tests/TypeScript/PathMapping/Imports.expected

@@ -0,0 +1,11 @@
+symbols
+| src/lib/foo.ts:1:1:4:0 | <toplevel> | library-tests/TypeScript/PathMapping/src/lib/foo.ts |
+| src/lib/foo.ts:1:8:3:1 | functio ...  123;\\n} | foo in library-tests/TypeScript/PathMapping/src/lib/foo.ts |
+| test/test_foo.ts:1:1:1:28 | import  ... @/foo"; | library-tests/TypeScript/PathMapping/src/lib/foo.ts |
+| test/test_foo.ts:1:1:7:0 | <toplevel> | library-tests/TypeScript/PathMapping/test/test_foo.ts |
+| test/test_foo.ts:2:17:2:32 | require("@/foo") | library-tests/TypeScript/PathMapping/src/lib/foo.ts |
+| test/test_foo.ts:4:1:4:5 | foo() | foo in library-tests/TypeScript/PathMapping/src/lib/foo.ts |
+| test/test_foo.ts:6:1:6:12 | foolib.foo() | foo in library-tests/TypeScript/PathMapping/src/lib/foo.ts |
+#select
+| test/test_foo.ts:1:1:1:28 | import  ... @/foo"; | src/lib/foo.ts:1:1:4:0 | <toplevel> |
+| test/test_foo.ts:2:17:2:32 | require("@/foo") | src/lib/foo.ts:1:1:4:0 | <toplevel> |

javascript/ql/test/library-tests/TypeScript/PathMapping/Imports.ql

@@ -0,0 +1,8 @@
+import javascript
+
+query predicate symbols(ASTNode astNode, CanonicalName symbol) {
+    ast_node_symbol(astNode, symbol)
+}
+
+from Import imprt
+select imprt, imprt.getImportedModule()

javascript/ql/test/library-tests/TypeScript/PathMapping/src/lib/foo.ts

@@ -0,0 +1,3 @@
+export function foo() {
+    return 123;
+}

javascript/ql/test/library-tests/TypeScript/PathMapping/test/test_foo.ts

@@ -0,0 +1,6 @@
+import { foo } from "@/foo";
+import foolib = require("@/foo");
+
+foo();
+
+foolib.foo();

javascript/ql/test/library-tests/TypeScript/PathMapping/tsconfig.json

@@ -0,0 +1,9 @@
+{
+    "include": ["."],
+    "compilerOptions": {
+        "baseUrl": ".",
+        "paths": {
+            "@/*": ["./src/lib/*"]
+        }
+    }
+}