Show implied options in --showConfig

src/compiler/commandLineParser.ts

@@ -15,6 +15,7 @@ import {
     CommandLineOptionOfListType,
     CompilerOptions,
     CompilerOptionsValue,
+    computedOptions,
     ConfigFileSpecs,
     containsPath,
     convertToRelativePath,
@@ -103,6 +104,7 @@ import {
     removeTrailingDirectorySeparator,
     returnTrue,
     ScriptTarget,
+    some,
     startsWith,
     StringLiteral,
     SyntaxKind,
@@ -2475,9 +2477,10 @@ export function convertToTSConfig(configParseResult: ParsedCommandLine, configFi
         ),
         f => getRelativePathFromFile(getNormalizedAbsolutePath(configFileName, host.getCurrentDirectory()), getNormalizedAbsolutePath(f, host.getCurrentDirectory()), getCanonicalFileName),
     );
-    const optionMap = serializeCompilerOptions(configParseResult.options, { configFilePath: getNormalizedAbsolutePath(configFileName, host.getCurrentDirectory()), useCaseSensitiveFileNames: host.useCaseSensitiveFileNames });
+    const pathOptions = { configFilePath: getNormalizedAbsolutePath(configFileName, host.getCurrentDirectory()), useCaseSensitiveFileNames: host.useCaseSensitiveFileNames };
+    const optionMap = serializeCompilerOptions(configParseResult.options, pathOptions);
     const watchOptionMap = configParseResult.watchOptions && serializeWatchOptions(configParseResult.watchOptions);
-    const config = {
+    const config: TSConfig & { watchOptions?: object; } = {
         compilerOptions: {
             ...optionMapToObject(optionMap),
             showConfig: undefined,
@@ -2500,6 +2503,19 @@ export function convertToTSConfig(configParseResult: ParsedCommandLine, configFi
         } : {}),
         compileOnSave: !!configParseResult.compileOnSave ? true : undefined,
     };
+
+    const providedKeys = new Set(optionMap.keys());
+    const impliedCompilerOptions: Record<string, CompilerOptionsValue> = {};
+    for (const option in computedOptions) {
+        if (!providedKeys.has(option) && some(computedOptions[option as keyof typeof computedOptions].dependencies, dep => providedKeys.has(dep))) {
+            const implied = computedOptions[option as keyof typeof computedOptions].computeValue(configParseResult.options);
+            const defaultValue = computedOptions[option as keyof typeof computedOptions].computeValue({});
+            if (implied !== defaultValue) {
+                impliedCompilerOptions[option] = computedOptions[option as keyof typeof computedOptions].computeValue(configParseResult.options);
+            }
+        }
+    }
+    assign(config.compilerOptions, optionMapToObject(serializeCompilerOptions(impliedCompilerOptions, pathOptions)));
     return config;
 }
 

tests/baselines/reference/config/showConfig/Show TSConfig with compileOnSave and more/tsconfig.json

@@ -3,7 +3,8 @@
         "esModuleInterop": true,
         "target": "es5",
         "module": "commonjs",
-        "strict": true
+        "strict": true,
+        "allowSyntheticDefaultImports": true
     },
     "references": [
         {

tests/baselines/reference/config/showConfig/Show TSConfig with paths and more/tsconfig.json

@@ -25,7 +25,8 @@
         },
         "experimentalDecorators": true,
         "emitDecoratorMetadata": true,
-        "resolveJsonModule": true
+        "resolveJsonModule": true,
+        "allowSyntheticDefaultImports": true
     },
     "include": [
         "./src/**/*"

tests/baselines/reference/config/showConfig/Shows tsconfig for single option/checkJs/tsconfig.json

@@ -1,5 +1,6 @@
 {
     "compilerOptions": {
-        "checkJs": true
+        "checkJs": true,
+        "allowJs": true
     }
 }

tests/baselines/reference/config/showConfig/Shows tsconfig for single option/composite/tsconfig.json

@@ -1,5 +1,7 @@
 {
     "compilerOptions": {
-        "composite": true
+        "composite": true,
+        "declaration": true,
+        "incremental": true
     }
 }

tests/baselines/reference/config/showConfig/Shows tsconfig for single option/isolatedModules/tsconfig.json

@@ -1,5 +1,6 @@
 {
     "compilerOptions": {
-        "isolatedModules": true
+        "isolatedModules": true,
+        "preserveConstEnums": true
     }
 }

tests/baselines/reference/config/showConfig/Shows tsconfig for single option/module/tsconfig.json

@@ -1,5 +1,6 @@
 {
     "compilerOptions": {
-        "module": "none"
+        "module": "none",
+        "moduleResolution": "classic"
     }
 }

tests/baselines/reference/config/showConfig/Shows tsconfig for single option/verbatimModuleSyntax/tsconfig.json

@@ -1,5 +1,7 @@
 {
     "compilerOptions": {
-        "verbatimModuleSyntax": true
+        "verbatimModuleSyntax": true,
+        "isolatedModules": true,
+        "preserveConstEnums": true
     }
 }