TypeScript: support TypeScript 3.0 features

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

@@ -686,6 +686,9 @@ class TypeExpr extends ExprOrType, @typeexpr {
   /** Holds if this is the `object` type. */
   predicate isObjectKeyword() { none() }
 
+  /** Holds if this is the `unknown` type. */
+  predicate isUnknownKeyword() { none() }
+
   /** Gets this type expression, with any surrounding parentheses removed. */
   override TypeExpr stripParens() {
     result = this
@@ -725,6 +728,7 @@ private class KeywordTypeExpr extends @keywordtypeexpr, TypeExpr {
   override predicate isSymbol() { getName() = "symbol" }
   override predicate isUniqueSymbol() { getName() = "unique symbol" }
   override predicate isObjectKeyword() { getName() = "object" }
+  override predicate isUnknownKeyword() { getName() = "unknown" }
 }
 
 /**
@@ -1073,6 +1077,25 @@ class IsTypeExpr extends @istypeexpr, TypeExpr {
   TypeExpr getPredicateType() { result = this.getChildTypeExpr(1) }
 }
 
+/**
+ * An optional type element in a tuple type, such as `number?` in `[string, number?]`.
+ */
+class OptionalTypeExpr extends @optionaltypeexpr, TypeExpr {
+  /** Gets the type `T` in `T?` */
+  TypeExpr getElementType() { result = getChildTypeExpr(0) }
+}
+
+/**
+ * A rest element in a tuple type, such as `...string[]` in `[number, ...string[]]`.
+ */
+class RestTypeExpr extends @resttypeexpr, TypeExpr {
+  /** Gets the type `T[]` in `...T[]`, such as `string[]` in `[number, ...string[]]`. */
+  TypeExpr getArrayType() { result = getChildTypeExpr(0) }
+
+  /** Gets the type `T` in `...T[]`, such as `string` in `[number, ...string[]]`. */
+  TypeExpr getElementType() { result = getArrayType().(ArrayTypeExpr).getElementType() }
+}
+
 /**
  * A possibly qualified name that refers to a variable from inside a type.
  *
@@ -2143,7 +2166,7 @@ class TupleType extends ArrayType, @tupletype {
   }
 
   /**
-   * Gets the number of elements in this tuple type.
+   * Gets the number of elements in this tuple type, including optional elements and the rest element.
    */
   int getNumElementType() {
     result = count(int i | exists(getElementType(i)))
@@ -2158,13 +2181,43 @@ class TupleType extends ArrayType, @tupletype {
   PlainArrayType getUnderlyingArrayType() {
     result.getArrayElementType() = getArrayElementType()
   }
+
+  /**
+   * Gets the number of required tuple elements, that is, excluding optional and rest elements.
+   *
+   * For example, the minimum length of `[number, string?, ...number[]]` is 1.
+   */
+  int getMinimumLength() {
+    tuple_type_min_length(this, result)
+  }
+
+  /**
+   * Holds if this tuple type ends with a rest element, such as `[number, ...string[]]`.
+   */
+  predicate hasRestElement() {
+    tuple_type_rest(this)
+  }
+
+  /**
+   * Gets the type of the rest element, if there is one.
+   *
+   * For example, the rest element of `[number, ...string[]]` is `string`.
+   */
+  Type getRestElementType() {
+    hasRestElement() and result = getElementType(getNumElementType() - 1)
+  }
 }
 
 /**
  * The predefined `any` type.
  */
 class AnyType extends Type, @anytype {}
 
+/**
+ * The predefined `unknown` type.
+ */
+class UnknownType extends Type, @unknowntype {}
+
 /**
  * The predefined `string` type.
  */

javascript/ql/src/semmlecode.javascript.dbscheme

@@ -556,7 +556,10 @@ case @typeexpr.kind of
 | 29 = @infertypeexpr
 | 30 = @importtypeaccess
 | 31 = @importnamespaceaccess
-| 32 = @importvartypeaccess;
+| 32 = @importvartypeaccess
+| 33 = @optionaltypeexpr
+| 34 = @resttypeexpr
+;
 
 @typeref = @typeaccess | @typedecl;
 @typeidentifier = @typedecl | @localtypeaccess | @typelabel | @localvartypeaccess | @localnamespaceaccess;
@@ -607,6 +610,7 @@ case @type.kind of
 | 20 = @thistype
 | 21 = @numberliteraltype
 | 22 = @stringliteraltype
+| 23 = @unknowntype
 ;
 
 @booleanliteraltype = @truetype | @falsetype;
@@ -734,6 +738,15 @@ self_types(
   int selfType: @typereference ref
 );
 
+tuple_type_min_length(
+  unique int typ: @type ref,
+  int minLength: int ref
+);
+
+tuple_type_rest(
+  unique int typ: @type ref
+);
+
 // comments
 comments (unique int id: @comment,
           int kind: int ref,

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

@@ -806,6 +806,14 @@
 <v>100</v>
 </e>
 <e>
+<k>@optionaltypeexpr</k>
+<v>100</v>
+</e>
+<e>
+<k>@resttypeexpr</k>
+<v>100</v>
+</e>
+<e>
 <k>@generictypeexpr</k>
 <v>5220</v>
 </e>
@@ -962,6 +970,10 @@
 <v>30638</v>
 </e>
 <e>
+<k>@unknowntype</k>
+<v>100</v>
+</e>
+<e>
 <k>@uniquesymboltype</k>
 <v>100</v>
 </e>
@@ -15385,6 +15397,100 @@
 </dependencies>
 </relation>
 <relation>
+<name>tuple_type_min_length</name>
+<cardinality>241</cardinality>
+<columnsizes>
+<e>
+<k>typ</k>
+<v>241</v>
+</e>
+<e>
+<k>minLength</k>
+<v>10</v>
+</e>
+</columnsizes>
+<dependencies>
+<dep>
+<src>typ</src>
+<trg>minLength</trg>
+<val>
+<hist>
+<budget>12</budget>
+<bs>
+<b>
+<a>1</a>
+<b>2</b>
+<v>241</v>
+</b>
+</bs>
+</hist>
+</val>
+</dep>
+<dep>
+<src>minLength</src>
+<trg>typ</trg>
+<val>
+<hist>
+<budget>12</budget>
+<bs>
+<b>
+<a>2</a>
+<b>3</b>
+<v>3</v>
+</b>
+<b>
+<a>3</a>
+<b>4</b>
+<v>1</v>
+</b>
+<b>
+<a>4</a>
+<b>5</b>
+<v>1</v>
+</b>
+<b>
+<a>7</a>
+<b>8</b>
+<v>1</v>
+</b>
+<b>
+<a>20</a>
+<b>21</b>
+<v>1</v>
+</b>
+<b>
+<a>42</a>
+<b>43</b>
+<v>1</v>
+</b>
+<b>
+<a>66</a>
+<b>67</b>
+<v>1</v>
+</b>
+<b>
+<a>93</a>
+<b>94</b>
+<v>1</v>
+</b>
+</bs>
+</hist>
+</val>
+</dep>
+</dependencies>
+</relation>
+<relation>
+<name>tuple_type_rest</name>
+<cardinality>100</cardinality>
+<columnsizes>
+<e>
+<k>typ</k>
+<v>100</v>
+</e>
+</columnsizes>
+<dependencies/>
+</relation>
+<relation>
 <name>comments</name>
 <key>id</key>
 <cardinality>104947</cardinality>

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/ArrayTypeExpr.expected

@@ -6,3 +6,5 @@
 | tst.ts:40:17:40:28 | string[][][] | tst.ts:40:17:40:26 | string[][] |
 | tst.ts:80:49:80:54 | Leaf[] | tst.ts:80:49:80:52 | Leaf |
 | tst.ts:81:27:81:34 | string[] | tst.ts:81:27:81:32 | string |
+| tst.ts:135:39:135:46 | string[] | tst.ts:135:39:135:44 | string |
+| tst.ts:136:60:136:67 | number[] | tst.ts:136:60:136:65 | number |

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/OptionalTypeExpr.expected

@@ -0,0 +1,2 @@
+| tst.ts:133:48:133:54 | number? | tst.ts:133:48:133:53 | number |
+| tst.ts:136:48:136:54 | string? | tst.ts:136:48:136:53 | string |

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/OptionalTypeExpr.ql

@@ -0,0 +1,4 @@
+import javascript
+
+from OptionalTypeExpr type
+select type, type.getElementType()

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/RestTypeExpr.expected

@@ -0,0 +1,2 @@
+| tst.ts:135:36:135:46 | ...string[] | tst.ts:135:39:135:46 | string[] | tst.ts:135:39:135:44 | string |
+| tst.ts:136:57:136:67 | ...number[] | tst.ts:136:60:136:67 | number[] | tst.ts:136:60:136:65 | number |

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/RestTypeExpr.ql

@@ -0,0 +1,4 @@
+import javascript
+
+from RestTypeExpr rest
+select rest, rest.getArrayType(), rest.getElementType()

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/TupleTypeExpr.expected

@@ -3,3 +3,11 @@
 | tst.ts:48:16:48:40 | [number ... oolean] | 2 | 3 | tst.ts:48:33:48:39 | boolean |
 | tst.ts:95:31:95:35 | [S,T] | 0 | 2 | tst.ts:95:32:95:32 | S |
 | tst.ts:95:31:95:35 | [S,T] | 1 | 2 | tst.ts:95:34:95:34 | T |
+| tst.ts:133:31:133:55 | [number ... umber?] | 0 | 3 | tst.ts:133:32:133:37 | number |
+| tst.ts:133:31:133:55 | [number ... umber?] | 1 | 3 | tst.ts:133:40:133:45 | string |
+| tst.ts:133:31:133:55 | [number ... umber?] | 2 | 3 | tst.ts:133:48:133:54 | number? |
+| tst.ts:135:27:135:47 | [number ... ring[]] | 0 | 2 | tst.ts:135:28:135:33 | number |
+| tst.ts:135:27:135:47 | [number ... ring[]] | 1 | 2 | tst.ts:135:36:135:46 | ...string[] |
+| tst.ts:136:39:136:68 | [number ... mber[]] | 0 | 3 | tst.ts:136:40:136:45 | number |
+| tst.ts:136:39:136:68 | [number ... mber[]] | 1 | 3 | tst.ts:136:48:136:54 | string? |
+| tst.ts:136:39:136:68 | [number ... mber[]] | 2 | 3 | tst.ts:136:57:136:67 | ...number[] |

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/UnknownTypeExpr.expected

@@ -0,0 +1 @@
+| tst.ts:137:18:137:24 | unknown |

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/UnknownTypeExpr.ql

@@ -0,0 +1,5 @@
+import javascript
+
+from TypeExpr type
+where type.isUnknownKeyword()
+select type

javascript/ql/test/library-tests/TypeScript/TypeAnnotations/VariableTypes.expected

@@ -69,3 +69,8 @@
 | tst.ts:126:5:126:18 | importedTypeof | importedTypeof | tst.ts:126:21:126:42 | typeof  ... value") |
 | tst.ts:127:5:127:27 | importe ... dTypeof | importedQualifiedTypeof | tst.ts:127:30:127:53 | typeof  ... lue").x |
 | tst.ts:128:5:128:35 | importe ... tespace | importedQualifiedTypeWhitespace | tst.ts:131:4:131:6 | bar |
+| tst.ts:133:5:133:28 | tupleWi ... Element | tupleWithOptionalElement | tst.ts:133:31:133:55 | [number ... umber?] |
+| tst.ts:134:5:134:14 | emptyTuple | emptyTuple | tst.ts:134:17:134:18 | [] |
+| tst.ts:135:5:135:24 | tupleWithRestElement | tupleWithRestElement | tst.ts:135:27:135:47 | [number ... ring[]] |
+| tst.ts:136:5:136:36 | tupleWi ... lements | tupleWithOptionalAndRestElements | tst.ts:136:39:136:68 | [number ... mber[]] |
+| tst.ts:137:5:137:15 | unknownType | unknownType | tst.ts:137:18:137:24 | unknown |

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

@@ -129,3 +129,9 @@ var importedQualifiedTypeWhitespace: import(
   'awkard-namespace'
   )
   .bar;
+
+let tupleWithOptionalElement: [number, string, number?];
+let emptyTuple: [];
+let tupleWithRestElement: [number, ...string[]];
+let tupleWithOptionalAndRestElements: [number, string?, ...number[]];
+let unknownType: unknown;

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

@@ -75,6 +75,11 @@
 | tst.ts:33:5:33:16 | intersection | string & { x: string; } |
 | tst.ts:33:29:33:29 | x | string |
 | tst.ts:34:5:34:9 | tuple | [number, string] |
+| tst.ts:36:5:36:28 | tupleWi ... Element | [number, string, number?] |
+| tst.ts:37:5:37:14 | emptyTuple | [] |
+| 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 |
 | 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/GetTypeExprType.expected

@@ -49,6 +49,25 @@
 | tst.ts:34:12:34:27 | [number, string] | [number, string] |
 | tst.ts:34:13:34:18 | number | number |
 | tst.ts:34:21:34:26 | string | string |
+| tst.ts:36:31:36:55 | [number ... umber?] | [number, string, number?] |
+| tst.ts:36:32:36:37 | number | number |
+| tst.ts:36:40:36:45 | string | string |
+| tst.ts:36:48:36:53 | number | number |
+| tst.ts:36:48:36:54 | number? | number |
+| tst.ts:37:17:37:18 | [] | [] |
+| tst.ts:38:27:38:47 | [number ... ring[]] | [number, ...string[]] |
+| tst.ts:38:28:38:33 | number | number |
+| tst.ts:38:36:38:46 | ...string[] | string[] |
+| tst.ts:38:39:38:44 | string | string |
+| tst.ts:38:39:38:46 | string[] | string[] |
+| tst.ts:39:39:39:68 | [number ... mber[]] | [number, string?, ...number[]] |
+| tst.ts:39:40:39:45 | number | number |
+| tst.ts:39:48:39:53 | string | string |
+| tst.ts:39:48:39:54 | string? | string |
+| tst.ts:39:57:39:67 | ...number[] | number[] |
+| tst.ts:39:60:39:65 | number | number |
+| tst.ts:39:60:39:67 | number[] | number[] |
+| tst.ts:40:18:40:24 | unknown | unknown |
 | 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 |

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

@@ -0,0 +1,10 @@
+| tst.ts:34:5:34:9 | tuple | [number, string] | 0 | number | 2 | no-rest |
+| tst.ts:34:5:34:9 | tuple | [number, string] | 1 | string | 2 | no-rest |
+| tst.ts:36:5:36:28 | tupleWi ... Element | [number, string, number?] | 0 | number | 2 | no-rest |
+| tst.ts:36:5:36:28 | tupleWi ... Element | [number, string, number?] | 1 | string | 2 | no-rest |
+| tst.ts:36:5:36:28 | tupleWi ... Element | [number, string, number?] | 2 | number | 2 | no-rest |
+| tst.ts:38:5:38:24 | tupleWithRestElement | [number, ...string[]] | 0 | number | 1 | string |
+| tst.ts:38:5:38:24 | tupleWithRestElement | [number, ...string[]] | 1 | string | 1 | string |
+| 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 |

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

@@ -0,0 +1,12 @@
+import javascript
+
+string getRest(TupleType tuple) {
+  if tuple.hasRestElement() then
+    result = tuple.getRestElementType().toString()
+  else
+    result = "no-rest"
+}
+
+from Expr e, TupleType tuple, int n
+where e.getType() = tuple
+select e, tuple, n, tuple.getElementType(n), tuple.getMinimumLength(), getRest(tuple)

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

@@ -0,0 +1 @@
+| tst.ts:40:5:40:15 | unknownType | unknown |

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

@@ -0,0 +1,5 @@
+import javascript
+
+from Expr e
+where e.getType() instanceof UnknownType
+select e, e.getType()