Merge pull request #1227 from asger-semmle/typescript3.4

Approved by xiemaisi

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

@@ -585,6 +585,9 @@ class TypeExpr extends ExprOrType, @typeexpr {
   /** Holds if this is the `bigint` type. */
   predicate isBigInt() { none() }
 
+  /** Holds if this is the `const` keyword, occurring in a type assertion such as `x as const`. */
+  predicate isConstKeyword() { none() }
+
   /** Gets this type expression, with any surrounding parentheses removed. */
   override TypeExpr stripParens() { result = this }
 
@@ -638,6 +641,8 @@ private class KeywordTypeExpr extends @keywordtypeexpr, TypeExpr {
   override predicate isUnknownKeyword() { getName() = "unknown" }
 
   override predicate isBigInt() { getName() = "bigint" }
+
+  override predicate isConstKeyword() { getName() = "const" }
 }
 
 /**
@@ -970,6 +975,14 @@ class RestTypeExpr extends @resttypeexpr, TypeExpr {
   TypeExpr getElementType() { result = getArrayType().(ArrayTypeExpr).getElementType() }
 }
 
+/**
+ * A type of form `readonly T`, such as `readonly number[]`.
+ */
+class ReadonlyTypeExpr extends @readonlytypeexpr, TypeExpr {
+  /** Gets the type `T` in `readonly T`. */
+  TypeExpr getElementType() { result = getChildTypeExpr(0) }
+}
+
 /**
  * A possibly qualified name that refers to a variable from inside a type.
  *

javascript/ql/src/semmlecode.javascript.dbscheme

@@ -573,6 +573,7 @@ case @typeexpr.kind of
 | 33 = @optionaltypeexpr
 | 34 = @resttypeexpr
 | 35 = @bigintliteraltypeexpr
+| 36 = @readonlytypeexpr
 ;
 
 @typeref = @typeaccess | @typedecl;

javascript/ql/src/semmlecode.javascript.dbscheme.stats

@@ -814,6 +814,10 @@
 <v>100</v>
 </e>
 <e>
+<k>@readonlytypeexpr</k>
+<v>100</v>
+</e>
+<e>
 <k>@bigintliteraltypeexpr</k>
 <v>100</v>
 </e>

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

@@ -1,16 +1,20 @@
 | (T \| ConcatArray<T>)[] | `T \| ConcatArray<T>` |
 | (number \| ConcatArray<number>)[] | `number \| ConcatArray<number>` |
+| (number[] \| ConcatArray<number[]>)[] | `number[] \| ConcatArray<number[]>` |
 | (string \| number \| ConcatArray<string \| number>)[] | `string \| number \| ConcatArray<string \| number>` |
 | (string \| number)[] | `string \| number` |
 | ConcatArray<T>[] | `ConcatArray<T>` |
 | ConcatArray<number>[] | `ConcatArray<number>` |
+| ConcatArray<number[]>[] | `ConcatArray<number[]>` |
 | ConcatArray<string \| number>[] | `ConcatArray<string \| number>` |
-| ReadonlyArray<T> | `T` |
-| ReadonlyArray<number> | `number` |
 | S[] | `S` |
 | T[] | `T` |
 | U[] | `U` |
 | [number, string] | `string \| number` |
 | any[] | `any` |
 | number[] | `number` |
+| number[][] | `number[]` |
+| readonly T[] | `T` |
+| readonly number[] | `number` |
+| readonly number[][] | `number[]` |
 | string[] | `string` |

javascript/ql/test/library-tests/TypeScript/ArrayTypes/NumberIndexTypes.expected

@@ -1,18 +1,22 @@
 | (T \| ConcatArray<T>)[] | T \| ConcatArray<T> |
 | (number \| ConcatArray<number>)[] | number \| ConcatArray<number> |
+| (number[] \| ConcatArray<number[]>)[] | number[] \| ConcatArray<number[]> |
 | (string \| number \| ConcatArray<string \| number>)[] | string \| number \| ConcatArray<string \| number> |
 | (string \| number)[] | string \| number |
 | ConcatArray<T>[] | ConcatArray<T> |
 | ConcatArray<number>[] | ConcatArray<number> |
+| ConcatArray<number[]>[] | ConcatArray<number[]> |
 | ConcatArray<string \| number>[] | ConcatArray<string \| number> |
 | NumberIndexable | object |
-| ReadonlyArray<T> | T |
-| ReadonlyArray<number> | number |
 | S[] | S |
 | T[] | T |
 | U[] | U |
 | [number, string] | string \| number |
 | any[] | any |
 | number[] | number |
+| number[][] | number[] |
+| readonly T[] | T |
+| readonly number[] | number |
+| readonly number[][] | number[] |
 | string | string |
 | string[] | string |

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

@@ -1,5 +1,5 @@
 let plain: number[];
-let radonly: ReadonlyArray<number>;
+let readonly: ReadonlyArray<number>;
 let tuple: [number, string];
 
 interface NumberIndexable {
@@ -14,3 +14,6 @@ interface StringIndexable {
 
 let numberIndexable: NumberIndexable;
 let stringIndexable: StringIndexable;
+
+let readonlySyntax: readonly number[];
+let readonlySyntax2: readonly number[][];

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

@@ -0,0 +1,6 @@
+test_ConstKeyword
+| tst.ts:1:19:1:23 | const |
+| tst.ts:2:10:2:14 | const |
+test_ConstTypeAssertion
+| tst.ts:1:9:1:23 | [1, 2] as const |
+| tst.ts:2:9:2:21 | <const>[1, 2] |

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

@@ -0,0 +1,9 @@
+import javascript
+
+query predicate test_ConstKeyword(TypeExpr t) {
+  t.isConstKeyword()
+}
+
+query predicate test_ConstTypeAssertion(TypeAssertion t) {
+  t.getTypeAnnotation().isConstKeyword()
+}

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

@@ -0,0 +1,2 @@
+var x = [1, 2] as const;
+var x = <const>[1, 2];

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

@@ -80,6 +80,16 @@
 | tst.ts:38:5:38:24 | tupleWithRestElement | [number, ...string[]] |
 | tst.ts:39:5:39:36 | tupleWi ... lements | [number, string?, ...number[]] |
 | tst.ts:40:5:40:15 | unknownType | unknown |
+| tst.ts:42:5:42:21 | constArrayLiteral | readonly [1, 2] |
+| tst.ts:42:25:42:30 | [1, 2] | readonly [1, 2] |
+| tst.ts:42:25:42:39 | [1, 2] as const | readonly [1, 2] |
+| tst.ts:42:26:42:26 | 1 | 1 |
+| tst.ts:42:29:42:29 | 2 | 2 |
+| tst.ts:43:5:43:22 | constObjectLiteral | { readonly foo: "foo"; } |
+| tst.ts:43:26:43:39 | { foo: "foo" } | { readonly foo: "foo"; } |
+| tst.ts:43:26:43:48 | { foo:  ... s const | { readonly foo: "foo"; } |
+| tst.ts:43:28:43:30 | foo | "foo" |
+| tst.ts:43:33:43:37 | "foo" | "foo" |
 | type_alias.ts:3:5:3:5 | b | boolean |
 | type_definition_objects.ts:1:13:1:17 | dummy | typeof dummy.ts |
 | type_definition_objects.ts:1:24:1:32 | "./dummy" | any |

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

@@ -8,3 +8,9 @@
 | tst.ts:39:5:39:36 | tupleWi ... lements | [number, string?, ...number[]] | 0 | number | 1 | number |
 | tst.ts:39:5:39:36 | tupleWi ... lements | [number, string?, ...number[]] | 1 | string | 1 | number |
 | tst.ts:39:5:39:36 | tupleWi ... lements | [number, string?, ...number[]] | 2 | number | 1 | number |
+| tst.ts:42:5:42:21 | constArrayLiteral | readonly [1, 2] | 0 | 1 | 2 | no-rest |
+| tst.ts:42:5:42:21 | constArrayLiteral | readonly [1, 2] | 1 | 2 | 2 | no-rest |
+| tst.ts:42:25:42:30 | [1, 2] | readonly [1, 2] | 0 | 1 | 2 | no-rest |
+| tst.ts:42:25:42:30 | [1, 2] | readonly [1, 2] | 1 | 2 | 2 | no-rest |
+| tst.ts:42:25:42:39 | [1, 2] as const | readonly [1, 2] | 0 | 1 | 2 | no-rest |
+| tst.ts:42:25:42:39 | [1, 2] as const | readonly [1, 2] | 1 | 2 | 2 | no-rest |

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

@@ -37,4 +37,7 @@ let tupleWithOptionalElement: [number, string, number?];
 let emptyTuple: [];
 let tupleWithRestElement: [number, ...string[]];
 let tupleWithOptionalAndRestElements: [number, string?, ...number[]];
-let unknownType: unknown;
+let unknownType: unknown;
+
+let constArrayLiteral = [1, 2] as const;
+let constObjectLiteral = { foo: "foo" } as const;