Function checkArrayLiteral

test/fixtures/snapshot/typescript.js:73346–73416

(node, checkMode, forceTuple)

                (node.kind === 221 /* SyntaxKind.BinaryExpression */ && node.operatorToken.kind === 63 /* SyntaxKind.EqualsToken */);
        }
        function checkArrayLiteral(node, checkMode, forceTuple) {
            var elements = node.elements;
            var elementCount = elements.length;
            var elementTypes = [];
            var elementFlags = [];
            var contextualType = getApparentTypeOfContextualType(node);
            var inDestructuringPattern = ts.isAssignmentTarget(node);
            var inConstContext = isConstContext(node);
            var hasOmittedExpression = false;
            for (var i = 0; i < elementCount; i++) {
                var e = elements[i];
                if (e.kind === 225 /* SyntaxKind.SpreadElement */) {
                    if (languageVersion < 2 /* ScriptTarget.ES2015 */) {
                        checkExternalEmitHelpers(e, compilerOptions.downlevelIteration ? 1536 /* ExternalEmitHelpers.SpreadIncludes */ : 1024 /* ExternalEmitHelpers.SpreadArray */);
                    }
                    var spreadType = checkExpression(e.expression, checkMode, forceTuple);
                    if (isArrayLikeType(spreadType)) {
                        elementTypes.push(spreadType);
                        elementFlags.push(8 /* ElementFlags.Variadic */);
                    }
                    else if (inDestructuringPattern) {
                        // Given the following situation:
                        //    var c: {};
                        //    [...c] = ["", 0];
                        //
                        // c is represented in the tree as a spread element in an array literal.
                        // But c really functions as a rest element, and its purpose is to provide
                        // a contextual type for the right hand side of the assignment. Therefore,
                        // instead of calling checkExpression on "...c", which will give an error
                        // if c is not iterable/array-like, we need to act as if we are trying to
                        // get the contextual element type from it. So we do something similar to
                        // getContextualTypeForElementExpression, which will crucially not error
                        // if there is no index type / iterated type.
                        var restElementType = getIndexTypeOfType(spreadType, numberType) ||
                            getIteratedTypeOrElementType(65 /* IterationUse.Destructuring */, spreadType, undefinedType, /*errorNode*/ undefined, /*checkAssignability*/ false) ||
                            unknownType;
                        elementTypes.push(restElementType);
                        elementFlags.push(4 /* ElementFlags.Rest */);
                    }
                    else {
                        elementTypes.push(checkIteratedTypeOrElementType(33 /* IterationUse.Spread */, spreadType, undefinedType, e.expression));
                        elementFlags.push(4 /* ElementFlags.Rest */);
                    }
                }
                else if (exactOptionalPropertyTypes && e.kind === 227 /* SyntaxKind.OmittedExpression */) {
                    hasOmittedExpression = true;
                    elementTypes.push(missingType);
                    elementFlags.push(2 /* ElementFlags.Optional */);
                }
                else {
                    var elementContextualType = getContextualTypeForElementExpression(contextualType, elementTypes.length);
                    var type = checkExpressionForMutableLocation(e, checkMode, elementContextualType, forceTuple);
                    elementTypes.push(addOptionality(type, /*isProperty*/ true, hasOmittedExpression));
                    elementFlags.push(hasOmittedExpression ? 2 /* ElementFlags.Optional */ : 1 /* ElementFlags.Required */);
                    if (contextualType && someType(contextualType, isTupleLikeType) && checkMode && checkMode & 2 /* CheckMode.Inferential */ && !(checkMode & 4 /* CheckMode.SkipContextSensitive */) && isContextSensitive(e)) {
                        var inferenceContext = getInferenceContext(node);
                        ts.Debug.assert(inferenceContext); // In CheckMode.Inferential we should always have an inference context
                        addIntraExpressionInferenceSite(inferenceContext, e, type);