support abstract signatures

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

@@ -947,6 +947,9 @@ export class TypeTable {
    * Returns a unique string for the given call/constructor signature.
    */
   private getSignatureString(kind: ts.SignatureKind, signature: AugmentedSignature): string {
+    let modifiers : ts.ModifiersArray = signature.getDeclaration()?.modifiers;
+    let isAbstract = modifiers && modifiers.filter(modifier => modifier.kind == ts.SyntaxKind.AbstractKeyword).length > 0
+
     let parameters = signature.getParameters();
     let numberOfTypeParameters = signature.typeParameters == null
         ? 0
@@ -978,7 +981,7 @@ export class TypeTable {
     if (returnTypeId == null) {
       return null;
     }
-    let tag = `${kind};${numberOfTypeParameters};${requiredParameters};${restParameterTag};${returnTypeId}`;
+    let tag = `${kind};${isAbstract ? "t" : "f"};${numberOfTypeParameters};${requiredParameters};${restParameterTag};${returnTypeId}`;
     for (let typeParameter of signature.typeParameters || []) {
       tag += ";" + typeParameter.symbol.name;
       let constraint = typeParameter.getConstraint();

javascript/extractor/src/com/semmle/ts/extractor/TypeExtractor.java

@@ -202,18 +202,22 @@ public class TypeExtractor {
 
   private void extractSignature(int index) {
     // Format is:
-    // kind;numTypeParams;requiredParams;restParamType;returnType(;paramName;paramType)*
+    // kind;isAbstract;numTypeParams;requiredParams;restParamType;returnType(;paramName;paramType)*
     String[] parts = split(table.getSignatureString(index));
     Label label = trapWriter.globalID("signature;" + index);
     int kind = Integer.parseInt(parts[0]);
-    int numberOfTypeParameters = Integer.parseInt(parts[1]);
+    boolean isAbstract = parts[1].equals("t");
-    int requiredParameters = Integer.parseInt(parts[2]);
+    if (isAbstract) {
-    String restParamTypeTag = parts[3];
+      trapWriter.addTuple("is_abstract_signature", label);
+    }
+    int numberOfTypeParameters = Integer.parseInt(parts[2]);
+    int requiredParameters = Integer.parseInt(parts[3]);
+    String restParamTypeTag = parts[4];
     if (!restParamTypeTag.isEmpty()) {
       trapWriter.addTuple(
           "signature_rest_parameter", label, trapWriter.globalID("type;" + restParamTypeTag));
     }
-    Label returnType = trapWriter.globalID("type;" + parts[4]);
+    Label returnType = trapWriter.globalID("type;" + parts[5]);
     trapWriter.addTuple(
         "signature_types",
         label,
@@ -222,9 +226,9 @@ public class TypeExtractor {
         numberOfTypeParameters,
         requiredParameters);
     trapWriter.addTuple("signature_contains_type", returnType, label, -1);
-    int numberOfParameters = (parts.length - 5) / 2; // includes type parameters
+    int numberOfParameters = (parts.length - 6) / 2; // includes type parameters
     for (int i = 0; i < numberOfParameters; ++i) {
-      int partIndex = 5 + (2 * i);
+      int partIndex = 6 + (2 * i);
       String paramName = parts[partIndex];
       String paramTypeId = parts[partIndex + 1];
       if (paramTypeId.length() > 0) { // Unconstrained type parameters have an empty type ID.

javascript/ql/src/semmle/javascript/TypeScript.qll

@@ -2794,6 +2794,11 @@ class CallSignatureType extends @signature_type {
    * For example, for the signature `(...y: string[])`, this gets the type `string[]`.
    */
   PlainArrayType getRestParameterArrayType() { signature_rest_parameter(this, result) }
+
+  /**
+   * Holds if this signature is abstract.
+   */
+  predicate isAbstract() { is_abstract_signature(this) }
 }
 
 /**

javascript/ql/src/semmlecode.javascript.dbscheme

@@ -742,6 +742,10 @@ signature_types (
   int required_params: int ref
 );
 
+is_abstract_signature(
+  unique int sig: @signature_type ref
+);
+
 signature_rest_parameter(
   unique int sig: @signature_type ref,
   int rest_param_arra_type: @type ref

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

@@ -107,6 +107,13 @@ getExprType
 | tst.ts:48:20:48:27 | "string" | "string" |
 | tst.ts:49:11:49:11 | b | string |
 | tst.ts:49:24:49:24 | e | string |
+| tst.ts:55:3:55:9 | getArea | () => number |
+| tst.ts:55:3:55:20 | getArea(): number; | () => number |
+| tst.ts:59:3:59:9 | getArea | () => number |
+| tst.ts:59:3:59:20 | getArea(): number; | () => number |
+| tst.ts:63:5:63:8 | Ctor | abstract new () => HasArea |
+| tst.ts:63:11:63:36 | abstrac ... HasArea | abstract new () => HasArea |
+| tst.ts:63:40:63:44 | Shape | any |
 | type_alias.ts:3:5:3:5 | b | boolean |
 | type_alias.ts:7:5:7:5 | c | ValueOrArray<number> |
 | type_alias.ts:14:9:14:32 | [proper ... ]: Json | any |
@@ -156,6 +163,8 @@ getExprType
 | type_definitions.ts:19:5:19:5 | e | EnumWithOneMember |
 | type_definitions.ts:22:5:22:23 | aliasForNumberArray | Alias<number> |
 getTypeDefinitionType
+| tst.ts:54:1:56:1 | interfa ... mber;\\n} | NonAbstractDummy |
+| tst.ts:58:1:60:1 | interfa ... mber;\\n} | HasArea |
 | type_alias.ts:1:1:1:17 | type B = boolean; | boolean |
 | type_alias.ts:5:1:5:50 | type Va ... ay<T>>; | ValueOrArray<T> |
 | type_alias.ts:9:1:15:13 | type Js ... Json[]; | Json |
@@ -245,6 +254,12 @@ getTypeExprType
 | tst.ts:39:60:39:67 | number[] | number[] |
 | tst.ts:40:18:40:24 | unknown | unknown |
 | tst.ts:49:15:49:20 | string | string |
+| tst.ts:54:11:54:26 | NonAbstractDummy | NonAbstractDummy |
+| tst.ts:55:14:55:19 | number | number |
+| tst.ts:58:11:58:17 | HasArea | HasArea |
+| tst.ts:59:14:59:19 | number | number |
+| tst.ts:63:11:63:36 | abstrac ... HasArea | abstract new () => HasArea |
+| tst.ts:63:30:63:36 | HasArea | HasArea |
 | type_alias.ts:1:6:1:6 | B | boolean |
 | type_alias.ts:1:10:1:16 | boolean | boolean |
 | type_alias.ts:3:8:3:8 | B | boolean |
@@ -317,9 +332,11 @@ referenceDefinition
 | Color.red | type_definitions.ts:14:3:14:5 | red |
 | E | type_definition_objects.ts:6:8:6:16 | enum E {} |
 | EnumWithOneMember | type_definitions.ts:18:26:18:31 | member |
+| HasArea | tst.ts:58:1:60:1 | interfa ... mber;\\n} |
 | I<S> | type_definitions.ts:3:1:5:1 | interfa ... x: S;\\n} |
 | I<number> | type_definitions.ts:3:1:5:1 | interfa ... x: S;\\n} |
 | Json | type_alias.ts:9:1:15:13 | type Js ... Json[]; |
+| NonAbstractDummy | tst.ts:54:1:56:1 | interfa ... mber;\\n} |
 | ValueOrArray<T> | type_alias.ts:5:1:5:50 | type Va ... ay<T>>; |
 | ValueOrArray<number> | type_alias.ts:5:1:5:50 | type Va ... ay<T>>; |
 | VirtualNode | type_alias.ts:19:1:21:57 | type Vi ... ode[]]; |
@@ -356,3 +373,6 @@ unknownType
 | tst.ts:40:5:40:15 | unknownType | unknown |
 | tst.ts:47:8:47:8 | e | unknown |
 | tst.ts:48:14:48:14 | e | unknown |
+abstractSignature
+| (): HasArea |
+| new (): HasArea |

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

@@ -35,3 +35,5 @@ query predicate unknownType(Expr e, Type type) {
   type = e.getType() and
   e.getType() instanceof UnknownType
 }
+
+query CallSignatureType abstractSignature() { result.isAbstract() }

javascript/ql/test/library-tests/TypeScript/Types/tst.ts

@@ -48,4 +48,16 @@ catch (e: unknown) {
   if (typeof e === "string") {
       let b : string = e;
   }
-}
+}
+
+
+interface NonAbstractDummy {
+  getArea(): number;
+}
+
+interface HasArea {
+  getArea(): number;
+}
+
+// abstract construct signature!
+let Ctor: abstract new () => HasArea = Shape;

javascript/upgrades/930898a4fe07cb48de46800904922ca118b31e50/is_abstract_signature.ql

@@ -0,0 +1,3 @@
+from int a, int b
+where none()
+select a, b

javascript/upgrades/930898a4fe07cb48de46800904922ca118b31e50/semmlecode.javascript.dbscheme

@@ -742,6 +742,10 @@ signature_types (
   int required_params: int ref
 );
 
+is_abstract_signature(
+  unique int sig: @signature_type ref
+);
+
 signature_rest_parameter(
   unique int sig: @signature_type ref,
   int rest_param_arra_type: @type ref

javascript/upgrades/930898a4fe07cb48de46800904922ca118b31e50/upgrade.properties

@@ -1,4 +1,5 @@
 description: add support for TypeScript 4.2
-compatibility: full
+compatibility: backwards
 tuple_type_rest_index.rel: run tuple_type_rest_index.qlo
-tuple_type_rest.rel: delete
+tuple_type_rest.rel: delete
+is_abstract_signature: run is_abstract_signature.qlo