Merge commit '6e92d2345e8231a44556ce7d416451f5f3e6c398' as 'engine262'

engine262/src/abstract-ops/notational-conventions.mts

@@ -0,0 +1,61 @@
+import {
+  ThrowCompletion, type Completion, type Value,
+} from '../index.mts';
+import { surroundingAgent } from '../host-defined/engine.mts';
+import type { ParseNode } from '../parser/ParseNode.mts';
+import { ObjectValue } from '../value.mts';
+
+class AssertError extends Error {}
+export function Assert(invariant: boolean, source?: string, completion?: Completion<unknown>): asserts invariant {
+  /* node:coverage disable */
+  if (!invariant) {
+    throw new AssertError(source, { cause: completion });
+  }
+  /* node:coverage enable */
+}
+Assert.Error = AssertError;
+Assert.Throw = (source?: string, completion?: Completion<unknown>) => {
+  /* node:coverage disable */
+  throw new AssertError(source, { cause: completion });
+  /* node:coverage enable */
+};
+
+/** https://tc39.es/ecma262/#sec-requireinternalslot */
+export function RequireInternalSlot(O: Value, internalSlot: string): ThrowCompletion | undefined {
+  if (!(O instanceof ObjectValue)) {
+    return surroundingAgent.Throw('TypeError', 'NotAnObject', O);
+  }
+  if (!(internalSlot in O)) {
+    return surroundingAgent.Throw('TypeError', 'InternalSlotMissing', O, internalSlot);
+  }
+  return undefined;
+}
+
+export function sourceTextMatchedBy(node: ParseNode) {
+  return node.sourceText;
+}
+
+// An ECMAScript Script syntactic unit may be processed using either unrestricted or strict mode syntax and semantics.
+// Code is interpreted as strict mode code in the following situations:
+//
+//  - Global code is strict mode code if it begins with a Directive Prologue that contains a Use Strict Directive.
+//
+//  - Module code is always strict mode code.
+//
+//  - All parts of a ClassDeclaration or a ClassExpression are strict mode code.
+//
+//  - Eval code is strict mode code if it begins with a Directive Prologue that contains a Use Strict Directive or
+//    if the call to eval is a direct eval that is contained in strict mode code.
+//
+//  - Function code is strict mode code if the associated FunctionDeclaration, FunctionExpression, GeneratorDeclaration,
+//    GeneratorExpression, AsyncFunctionDeclaration, AsyncFunctionExpression, AsyncGeneratorDeclaration,
+//    AsyncGeneratorExpression, MethodDefinition, ArrowFunction, or AsyncArrowFunction is contained in strict mode code
+//    or if the code that produces the value of the function's [[ECMAScriptCode]] internal slot begins with a Directive
+//    Prologue that contains a Use Strict Directive.
+//
+//  - Function code that is supplied as the arguments to the built-in Function, Generator, AsyncFunction, and
+//    AsyncGenerator constructors is strict mode code if the last argument is a String that when processed is a
+//    FunctionBody that begins with a Directive Prologue that contains a Use Strict Directive.
+export function isStrictModeCode(node: ParseNode) {
+  return node.strict;
+}