Function getContextualThisParameterType

test/fixtures/snapshot/typescript.js:72339–72397

(func)

            });
        }
        function getContextualThisParameterType(func) {
            if (func.kind === 214 /* SyntaxKind.ArrowFunction */) {
                return undefined;
            }
            if (isContextSensitiveFunctionOrObjectLiteralMethod(func)) {
                var contextualSignature = getContextualSignature(func);
                if (contextualSignature) {
                    var thisParameter = contextualSignature.thisParameter;
                    if (thisParameter) {
                        return getTypeOfSymbol(thisParameter);
                    }
                }
            }
            var inJs = ts.isInJSFile(func);
            if (noImplicitThis || inJs) {
                var containingLiteral = getContainingObjectLiteral(func);
                if (containingLiteral) {
                    // We have an object literal method. Check if the containing object literal has a contextual type
                    // that includes a ThisType<T>. If so, T is the contextual type for 'this'. We continue looking in
                    // any directly enclosing object literals.
                    var contextualType = getApparentTypeOfContextualType(containingLiteral);
                    var literal = containingLiteral;
                    var type = contextualType;
                    while (type) {
                        var thisType = getThisTypeFromContextualType(type);
                        if (thisType) {
                            return instantiateType(thisType, getMapperFromContext(getInferenceContext(containingLiteral)));
                        }
                        if (literal.parent.kind !== 296 /* SyntaxKind.PropertyAssignment */) {
                            break;
                        }
                        literal = literal.parent.parent;
                        type = getApparentTypeOfContextualType(literal);
                    }
                    // There was no contextual ThisType<T> for the containing object literal, so the contextual type
                    // for 'this' is the non-null form of the contextual type for the containing object literal or
                    // the type of the object literal itself.
                    return getWidenedType(contextualType ? getNonNullableType(contextualType) : checkExpressionCached(containingLiteral));
                }
                // In an assignment of the form 'obj.xxx = function(...)' or 'obj[xxx] = function(...)', the
                // contextual type for 'this' is 'obj'.
                var parent = ts.walkUpParenthesizedExpressions(func.parent);
                if (parent.kind === 221 /* SyntaxKind.BinaryExpression */ && parent.operatorToken.kind === 63 /* SyntaxKind.EqualsToken */) {
                    var target = parent.left;
                    if (ts.isAccessExpression(target)) {
                        var expression = target.expression;
                        // Don't contextually type `this` as `exports` in `exports.Point = function(x, y) { this.x = x; this.y = y; }`
                        if (inJs && ts.isIdentifier(expression)) {
                            var sourceFile = ts.getSourceFileOfNode(parent);
                            if (sourceFile.commonJsModuleIndicator && getResolvedSymbol(expression) === sourceFile.symbol) {
                                return undefined;
                            }
                        }
                        return getWidenedType(checkExpressionCached(expression));
                    }
                }
            }
            return undefined;