Function verifyEmitFilePath

test/fixtures/snapshot/typescript.js:118917–118940

(emitFileName, emitFilesSeen)

            }
            // Verify that all the emit files are unique and don't overwrite input files
            function verifyEmitFilePath(emitFileName, emitFilesSeen) {
                if (emitFileName) {
                    var emitFilePath = toPath(emitFileName);
                    // Report error if the output overwrites input file
                    if (filesByName.has(emitFilePath)) {
                        var chain = void 0;
                        if (!options.configFilePath) {
                            // The program is from either an inferred project or an external project
                            chain = ts.chainDiagnosticMessages(/*details*/ undefined, ts.Diagnostics.Adding_a_tsconfig_json_file_will_help_organize_projects_that_contain_both_TypeScript_and_JavaScript_files_Learn_more_at_https_Colon_Slash_Slashaka_ms_Slashtsconfig);
                        }
                        chain = ts.chainDiagnosticMessages(chain, ts.Diagnostics.Cannot_write_file_0_because_it_would_overwrite_input_file, emitFileName);
                        blockEmittingOfFile(emitFileName, ts.createCompilerDiagnosticFromMessageChain(chain));
                    }
                    var emitFileKey = !host.useCaseSensitiveFileNames() ? ts.toFileNameLowerCase(emitFilePath) : emitFilePath;
                    // Report error if multiple files write into same file
                    if (emitFilesSeen.has(emitFileKey)) {
                        // Already seen the same emit file - report error
                        blockEmittingOfFile(emitFileName, ts.createCompilerDiagnostic(ts.Diagnostics.Cannot_write_file_0_because_it_would_be_overwritten_by_multiple_input_files, emitFileName));
                    }
                    else {
                        emitFilesSeen.add(emitFileKey);
                    }
                }
            }
        }
        function createDiagnosticExplainingFile(file, fileProcessingReason, diagnostic, args) {
            var _a;