Add showConfig tsc flag for debugging configs (#27353)

* Add showConfig tsc flag for debugging configs

* Merge showConfig implementation with init implementation, add basic unit tests

* Fix lint

* Add missing semicolon

* showConfig when theres no config file

Author: weswigham

src/compiler/commandLineParser.ts

@@ -164,6 +164,13 @@ namespace ts {
             category: Diagnostics.Command_line_Options,
             description: Diagnostics.Stylize_errors_and_messages_using_color_and_context_experimental
         },
+        {
+            name: "showConfig",
+            type: "boolean",
+            category: Diagnostics.Command_line_Options,
+            isCommandLineOnly: true,
+            description: Diagnostics.Print_the_final_configuration_instead_of_building
+        },
 
         // Basic
         {
@@ -1654,72 +1661,146 @@ namespace ts {
     }
 
     /**
-     * Generate tsconfig configuration when running command line "--init"
-     * @param options commandlineOptions to be generated into tsconfig.json
-     * @param fileNames array of filenames to be generated into tsconfig.json
+     * Generate an uncommented, complete tsconfig for use with "--showConfig"
+     * @param configParseResult options to be generated into tsconfig.json
+     * @param configFileName name of the parsed config file - output paths will be generated relative to this
+     * @param host provides current directory and case sensitivity services
      */
-    /* @internal */
-    export function generateTSConfig(options: CompilerOptions, fileNames: ReadonlyArray<string>, newLine: string): string {
-        const compilerOptions = extend(options, defaultInitCompilerOptions);
-        const compilerOptionsMap = serializeCompilerOptions(compilerOptions);
-        return writeConfigurations();
+    /** @internal */
+    export function convertToTSConfig(configParseResult: ParsedCommandLine, configFileName: string, host: { getCurrentDirectory(): string, useCaseSensitiveFileNames: boolean }): object {
+        const getCanonicalFileName = createGetCanonicalFileName(host.useCaseSensitiveFileNames);
+        const files = map(
+            filter(
+                configParseResult.fileNames,
+                !configParseResult.configFileSpecs ? _ => false : matchesSpecs(
+                    configFileName,
+                    configParseResult.configFileSpecs.validatedIncludeSpecs,
+                    configParseResult.configFileSpecs.validatedExcludeSpecs
+                )
+            ),
+            f => getRelativePathFromFile(getNormalizedAbsolutePath(configFileName, host.getCurrentDirectory()), f, getCanonicalFileName)
+        );
+        const optionMap = serializeCompilerOptions(configParseResult.options, { configFilePath: getNormalizedAbsolutePath(configFileName, host.getCurrentDirectory()), useCaseSensitiveFileNames: host.useCaseSensitiveFileNames });
+        const config = {
+            compilerOptions: {
+                ...arrayFrom(optionMap.entries()).reduce((prev, cur) => ({ ...prev, [cur[0]]: cur[1] }), {}),
+                showConfig: undefined,
+                configFile: undefined,
+                configFilePath: undefined,
+                help: undefined,
+                init: undefined,
+                listFiles: undefined,
+                listEmittedFiles: undefined,
+                project: undefined,
+            },
+            references: map(configParseResult.projectReferences, r => ({ ...r, path: r.originalPath, originalPath: undefined })),
+            files: length(files) ? files : undefined,
+            ...(configParseResult.configFileSpecs ? {
+                include: filterSameAsDefaultInclude(configParseResult.configFileSpecs.validatedIncludeSpecs),
+                exclude: configParseResult.configFileSpecs.validatedExcludeSpecs
+            } : {}),
+            compilerOnSave: !!configParseResult.compileOnSave ? true : undefined
+        };
+        return config;
+    }
 
-        function getCustomTypeMapOfCommandLineOption(optionDefinition: CommandLineOption): Map<string | number> | undefined {
-            if (optionDefinition.type === "string" || optionDefinition.type === "number" || optionDefinition.type === "boolean") {
-                // this is of a type CommandLineOptionOfPrimitiveType
-                return undefined;
-            }
-            else if (optionDefinition.type === "list") {
-                return getCustomTypeMapOfCommandLineOption(optionDefinition.element);
-            }
-            else {
-                return (<CommandLineOptionOfCustomType>optionDefinition).type;
+    function filterSameAsDefaultInclude(specs: ReadonlyArray<string> | undefined) {
+        if (!length(specs)) return undefined;
+        if (length(specs) !== 1) return specs;
+        if (specs![0] === "**/*") return undefined;
+        return specs;
+    }
+
+    function matchesSpecs(path: string, includeSpecs: ReadonlyArray<string> | undefined, excludeSpecs: ReadonlyArray<string> | undefined): (path: string) => boolean {
+        if (!includeSpecs) return _ => false;
+        const patterns = getFileMatcherPatterns(path, excludeSpecs, includeSpecs, sys.useCaseSensitiveFileNames, sys.getCurrentDirectory());
+        const excludeRe = patterns.excludePattern && getRegexFromPattern(patterns.excludePattern, sys.useCaseSensitiveFileNames);
+        const includeRe = patterns.includeFilePattern && getRegexFromPattern(patterns.includeFilePattern, sys.useCaseSensitiveFileNames);
+        if (includeRe) {
+            if (excludeRe) {
+                return path => includeRe.test(path) && !excludeRe.test(path);
             }
+            return path => includeRe.test(path);
+        }
+        if (excludeRe) {
+            return path => !excludeRe.test(path);
         }
+        return _ => false;
+    }
 
-        function getNameOfCompilerOptionValue(value: CompilerOptionsValue, customTypeMap: Map<string | number>): string | undefined {
-            // There is a typeMap associated with this command-line option so use it to map value back to its name
-            return forEachEntry(customTypeMap, (mapValue, key) => {
-                if (mapValue === value) {
-                    return key;
-                }
-            });
+    function getCustomTypeMapOfCommandLineOption(optionDefinition: CommandLineOption): Map<string | number> | undefined {
+        if (optionDefinition.type === "string" || optionDefinition.type === "number" || optionDefinition.type === "boolean") {
+            // this is of a type CommandLineOptionOfPrimitiveType
+            return undefined;
+        }
+        else if (optionDefinition.type === "list") {
+            return getCustomTypeMapOfCommandLineOption(optionDefinition.element);
+        }
+        else {
+            return (<CommandLineOptionOfCustomType>optionDefinition).type;
         }
+    }
 
-        function serializeCompilerOptions(options: CompilerOptions): Map<CompilerOptionsValue> {
-            const result = createMap<CompilerOptionsValue>();
-            const optionsNameMap = getOptionNameMap().optionNameMap;
+    function getNameOfCompilerOptionValue(value: CompilerOptionsValue, customTypeMap: Map<string | number>): string | undefined {
+        // There is a typeMap associated with this command-line option so use it to map value back to its name
+        return forEachEntry(customTypeMap, (mapValue, key) => {
+            if (mapValue === value) {
+                return key;
+            }
+        });
+    }
 
-            for (const name in options) {
-                if (hasProperty(options, name)) {
-                    // tsconfig only options cannot be specified via command line,
-                    // so we can assume that only types that can appear here string | number | boolean
-                    if (optionsNameMap.has(name) && optionsNameMap.get(name)!.category === Diagnostics.Command_line_Options) {
-                        continue;
-                    }
-                    const value = <CompilerOptionsValue>options[name];
-                    const optionDefinition = optionsNameMap.get(name.toLowerCase());
-                    if (optionDefinition) {
-                        const customTypeMap = getCustomTypeMapOfCommandLineOption(optionDefinition);
-                        if (!customTypeMap) {
-                            // There is no map associated with this compiler option then use the value as-is
-                            // This is the case if the value is expect to be string, number, boolean or list of string
+    function serializeCompilerOptions(options: CompilerOptions, pathOptions?: { configFilePath: string, useCaseSensitiveFileNames: boolean }): Map<CompilerOptionsValue> {
+        const result = createMap<CompilerOptionsValue>();
+        const optionsNameMap = getOptionNameMap().optionNameMap;
+        const getCanonicalFileName = pathOptions && createGetCanonicalFileName(pathOptions.useCaseSensitiveFileNames);
+
+        for (const name in options) {
+            if (hasProperty(options, name)) {
+                // tsconfig only options cannot be specified via command line,
+                // so we can assume that only types that can appear here string | number | boolean
+                if (optionsNameMap.has(name) && optionsNameMap.get(name)!.category === Diagnostics.Command_line_Options) {
+                    continue;
+                }
+                const value = <CompilerOptionsValue>options[name];
+                const optionDefinition = optionsNameMap.get(name.toLowerCase());
+                if (optionDefinition) {
+                    const customTypeMap = getCustomTypeMapOfCommandLineOption(optionDefinition);
+                    if (!customTypeMap) {
+                        // There is no map associated with this compiler option then use the value as-is
+                        // This is the case if the value is expect to be string, number, boolean or list of string
+                        if (pathOptions && optionDefinition.isFilePath) {
+                            result.set(name, getRelativePathFromFile(pathOptions.configFilePath, getNormalizedAbsolutePath(value as string, getDirectoryPath(pathOptions.configFilePath)), getCanonicalFileName!));
+                        }
+                        else {
                             result.set(name, value);
                         }
+                    }
+                    else {
+                        if (optionDefinition.type === "list") {
+                            result.set(name, (value as ReadonlyArray<string | number>).map(element => getNameOfCompilerOptionValue(element, customTypeMap)!)); // TODO: GH#18217
+                        }
                         else {
-                            if (optionDefinition.type === "list") {
-                                result.set(name, (value as ReadonlyArray<string | number>).map(element => getNameOfCompilerOptionValue(element, customTypeMap)!)); // TODO: GH#18217
-                            }
-                            else {
-                                // There is a typeMap associated with this command-line option so use it to map value back to its name
-                                result.set(name, getNameOfCompilerOptionValue(value, customTypeMap));
-                            }
+                            // There is a typeMap associated with this command-line option so use it to map value back to its name
+                            result.set(name, getNameOfCompilerOptionValue(value, customTypeMap));
                         }
                     }
                 }
             }
-            return result;
         }
+        return result;
+    }
+
+    /**
+     * Generate tsconfig configuration when running command line "--init"
+     * @param options commandlineOptions to be generated into tsconfig.json
+     * @param fileNames array of filenames to be generated into tsconfig.json
+     */
+    /* @internal */
+    export function generateTSConfig(options: CompilerOptions, fileNames: ReadonlyArray<string>, newLine: string): string {
+        const compilerOptions = extend(options, defaultInitCompilerOptions);
+        const compilerOptionsMap = serializeCompilerOptions(compilerOptions);
+        return writeConfigurations();
 
         function getDefaultValueForOption(option: CommandLineOption) {
             switch (option.type) {

src/compiler/diagnosticMessages.json

@@ -1007,6 +1007,10 @@
         "category": "Error",
         "code": 1349
     },
+    "Print the final configuration instead of building.": {
+        "category": "Message",
+        "code": 1350
+    },
 
     "Duplicate identifier '{0}'.": {
         "category": "Error",

src/compiler/types.ts

@@ -4556,6 +4556,7 @@ namespace ts {
         /*@internal*/ version?: boolean;
         /*@internal*/ watch?: boolean;
         esModuleInterop?: boolean;
+        /* @internal */ showConfig?: boolean;
 
         [option: string]: CompilerOptionsValue | TsConfigSourceFile | undefined;
     }

src/testRunner/tsconfig.json

@@ -75,6 +75,7 @@
         "unittests/reuseProgramStructure.ts",
         "unittests/session.ts",
         "unittests/semver.ts",
+        "unittests/showConfig.ts",
         "unittests/symbolWalker.ts",
         "unittests/telemetry.ts",
         "unittests/textChanges.ts",

src/testRunner/unittests/showConfig.ts

@@ -0,0 +1,34 @@
+namespace ts {
+    describe("showTSConfig", () => {
+        function showTSConfigCorrectly(name: string, commandLinesArgs: string[]) {
+            describe(name, () => {
+                const commandLine = parseCommandLine(commandLinesArgs);
+                const initResult = convertToTSConfig(commandLine, `/${name}/tsconfig.json`, { getCurrentDirectory() { return `/${name}`; }, useCaseSensitiveFileNames: true });
+                const outputFileName = `showConfig/${name.replace(/[^a-z0-9\-. ]/ig, "")}/tsconfig.json`;
+
+                it(`Correct output for ${outputFileName}`, () => {
+                    // tslint:disable-next-line:no-null-keyword
+                    Harness.Baseline.runBaseline(outputFileName, JSON.stringify(initResult, null, 4) + "\n");
+                });
+            });
+        }
+
+        showTSConfigCorrectly("Default initialized TSConfig", ["--showConfig"]);
+
+        showTSConfigCorrectly("Show TSConfig with files options", ["--showConfig", "file0.st", "file1.ts", "file2.ts"]);
+
+        showTSConfigCorrectly("Show TSConfig with boolean value compiler options", ["--showConfig", "--noUnusedLocals"]);
+
+        showTSConfigCorrectly("Show TSConfig with enum value compiler options", ["--showConfig", "--target", "es5", "--jsx", "react"]);
+
+        showTSConfigCorrectly("Show TSConfig with list compiler options", ["--showConfig", "--types", "jquery,mocha"]);
+
+        showTSConfigCorrectly("Show TSConfig with list compiler options with enum value", ["--showConfig", "--lib", "es5,es2015.core"]);
+
+        showTSConfigCorrectly("Show TSConfig with incorrect compiler option", ["--showConfig", "--someNonExistOption"]);
+
+        showTSConfigCorrectly("Show TSConfig with incorrect compiler option value", ["--showConfig", "--lib", "nonExistLib,es5,es2015.promise"]);
+
+        showTSConfigCorrectly("Show TSConfig with advanced options", ["--showConfig", "--declaration", "--declarationDir", "lib", "--skipLibCheck", "--noErrorTruncation"]);
+    });
+}

src/tsc/tsc.ts

@@ -132,6 +132,11 @@ namespace ts {
         const commandLineOptions = commandLine.options;
         if (configFileName) {
             const configParseResult = parseConfigFileWithSystem(configFileName, commandLineOptions, sys, reportDiagnostic)!; // TODO: GH#18217
+            if (commandLineOptions.showConfig) {
+                // tslint:disable-next-line:no-null-keyword
+                sys.write(JSON.stringify(convertToTSConfig(configParseResult, configFileName, sys), null, 4) + sys.newLine);
+                return sys.exit(ExitStatus.Success);
+            }
             updateReportDiagnostic(configParseResult.options);
             if (isWatchSet(configParseResult.options)) {
                 reportWatchModeWithoutSysSupport();
@@ -142,6 +147,11 @@ namespace ts {
             }
         }
         else {
+            if (commandLineOptions.showConfig) {
+                // tslint:disable-next-line:no-null-keyword
+                sys.write(JSON.stringify(convertToTSConfig(commandLine, combinePaths(sys.getCurrentDirectory(), "tsconfig.json"), sys), null, 4) + sys.newLine);
+                return sys.exit(ExitStatus.Success);
+            }
             updateReportDiagnostic(commandLineOptions);
             if (isWatchSet(commandLineOptions)) {
                 reportWatchModeWithoutSysSupport();

tests/baselines/reference/showConfig/Default initialized TSConfig/tsconfig.json

@@ -0,0 +1,3 @@
+{
+    "compilerOptions": {}
+}

tests/baselines/reference/showConfig/Show TSConfig with advanced options/tsconfig.json

@@ -0,0 +1,8 @@
+{
+    "compilerOptions": {
+        "declaration": true,
+        "declarationDir": "./lib",
+        "skipLibCheck": true,
+        "noErrorTruncation": true
+    }
+}

tests/baselines/reference/showConfig/Show TSConfig with boolean value compiler options/tsconfig.json

@@ -0,0 +1,5 @@
+{
+    "compilerOptions": {
+        "noUnusedLocals": true
+    }
+}

tests/baselines/reference/showConfig/Show TSConfig with enum value compiler options/tsconfig.json

@@ -0,0 +1,6 @@
+{
+    "compilerOptions": {
+        "target": "es5",
+        "jsx": "react"
+    }
+}

tests/baselines/reference/showConfig/Show TSConfig with files options/tsconfig.json

@@ -0,0 +1,3 @@
+{
+    "compilerOptions": {}
+}

tests/baselines/reference/showConfig/Show TSConfig with incorrect compiler option value/tsconfig.json

@@ -0,0 +1,8 @@
+{
+    "compilerOptions": {
+        "lib": [
+            "es5",
+            "es2015.promise"
+        ]
+    }
+}

tests/baselines/reference/showConfig/Show TSConfig with incorrect compiler option/tsconfig.json

@@ -0,0 +1,3 @@
+{
+    "compilerOptions": {}
+}

tests/baselines/reference/showConfig/Show TSConfig with list compiler options with enum value/tsconfig.json

@@ -0,0 +1,8 @@
+{
+    "compilerOptions": {
+        "lib": [
+            "es5",
+            "es2015.core"
+        ]
+    }
+}

tests/baselines/reference/showConfig/Show TSConfig with list compiler options/tsconfig.json

@@ -0,0 +1,8 @@
+{
+    "compilerOptions": {
+        "types": [
+            "jquery",
+            "mocha"
+        ]
+    }
+}