Function createLazyCaseClauseDiagnostics

test/fixtures/snapshot/typescript.js:83719–83736

(clause)

                    error(clause, ts.Diagnostics.Fallthrough_case_in_switch);
                }
                function createLazyCaseClauseDiagnostics(clause) {
                    return function () {
                        // TypeScript 1.0 spec (April 2014): 5.9
                        // In a 'switch' statement, each 'case' expression must be of a type that is comparable
                        // to or from the type of the 'switch' expression.
                        var caseType = checkExpression(clause.expression);
                        var caseIsLiteral = isLiteralType(caseType);
                        var comparedExpressionType = expressionType;
                        if (!caseIsLiteral || !expressionIsLiteral) {
                            caseType = caseIsLiteral ? getBaseTypeOfLiteralType(caseType) : caseType;
                            comparedExpressionType = getBaseTypeOfLiteralType(expressionType);
                        }
                        if (!isTypeEqualityComparableTo(comparedExpressionType, caseType)) {
                            // expressionType is not comparable to caseType, try the reversed check and report errors if it fails
                            checkTypeComparableTo(caseType, comparedExpressionType, clause.expression, /*headMessage*/ undefined);
                        }
                    };
                }
            });
            if (node.caseBlock.locals) {
                registerForUnusedIdentifiersCheck(node.caseBlock);