Fix(29118): tsconfig.extends as array

src/compiler/builder.ts

@@ -994,6 +994,7 @@ namespace ts {
 
     function convertToReusableCompilerOptionValue(option: CommandLineOption | undefined, value: CompilerOptionsValue, relativeToBuildInfo: (path: string) => string) {
         if (option) {
+            Debug.assert(option.type !== "listOrElement");
             if (option.type === "list") {
                 const values = value as readonly (string | number)[];
                 if (option.element.isFilePath && values.length) {

src/compiler/types.ts

@@ -6598,7 +6598,7 @@ namespace ts {
     /* @internal */
     export interface CommandLineOptionBase {
         name: string;
-        type: "string" | "number" | "boolean" | "object" | "list" | ESMap<string, number | string>;    // a value of a primitive type, or an object literal mapping named values to actual values
+        type: "string" | "number" | "boolean" | "object" | "list" | "listOrElement" | ESMap<string, number | string> ;    // a value of a primitive type, or an object literal mapping named values to actual values
         isFilePath?: boolean;                                   // True if option value is a path or fileName
         shortName?: string;                                     // A short mnemonic for convenience - for instance, 'h' can be used in place of 'help'
         description?: DiagnosticMessage;                        // The message describing what the command line switch does.
@@ -6669,7 +6669,7 @@ namespace ts {
 
     /* @internal */
     export interface CommandLineOptionOfListType extends CommandLineOptionBase {
-        type: "list";
+        type: "list" | "listOrElement";
         element: CommandLineOptionOfCustomType | CommandLineOptionOfStringType | CommandLineOptionOfNumberType | CommandLineOptionOfBooleanType | TsConfigOnlyOption;
         listPreserveFalsyValues?: boolean;
     }

src/executeCommandLine/executeCommandLine.ts

@@ -163,7 +163,8 @@ namespace ts {
         const defaultValueDescription =
             typeof option.defaultValueDescription === "object"
                 ? getDiagnosticText(option.defaultValueDescription)
-                : formatDefaultValue(
+                : Debug.assert(option.type !== "listOrElement");
+                    formatDefaultValue(
                       option.defaultValueDescription,
                       option.type === "list" ? option.element.type : option.type
                   );
@@ -276,6 +277,7 @@ namespace ts {
             };
 
             function getValueType(option: CommandLineOption) {
+                Debug.assert(option.type !== "listOrElement");
                 switch (option.type) {
                     case "string":
                     case "number":
@@ -297,7 +299,7 @@ namespace ts {
                         possibleValues = option.type;
                         break;
                     case "list":
-                        // TODO: check infinite loop
+                    case "listOrElement":
                         possibleValues = getPossibleValues(option.element);
                         break;
                     case "object":

src/services/getEditsForFileRename.ts

@@ -73,6 +73,7 @@ namespace ts {
                 case "compilerOptions":
                     forEachProperty(property.initializer, (property, propertyName) => {
                         const option = getOptionFromName(propertyName);
+                        Debug.assert(option?.type !== "listOrElement");
                         if (option && (option.isFilePath || option.type === "list" && option.element.isFilePath)) {
                             updatePaths(property);
                         }

src/testRunner/unittests/config/configurationExtension.ts

@@ -183,7 +183,47 @@ namespace ts {
                     "dev/tests/unit/spec.ts": "",
                     "dev/tests/utils.ts": "",
                     "dev/tests/scenarios/first.json": "",
-                    "dev/tests/baselines/first/output.ts": ""
+                    "dev/tests/baselines/first/output.ts": "",
+                    "dev/configs/extendsArrayFirst.json": JSON.stringify({
+                        compilerOptions: {
+                            allowJs: true,
+                            noImplicitAny: true,
+                            strictNullChecks: true
+                        }
+                    }),
+                    "dev/configs/extendsArraySecond.json": JSON.stringify({
+                        compilerOptions: {
+                            module: "amd"
+                        },
+                        include: ["../supplemental.*"]
+                    }),
+                    "dev/configs/extendsArrayThird.json": JSON.stringify({
+                        compilerOptions: {
+                            module: null, // eslint-disable-line no-null/no-null
+                            noImplicitAny: false
+                        },
+                        extends: "./extendsArrayFirst",
+                        include: ["../supplemental.*"]
+                    }),
+                    "dev/configs/extendsArrayFourth.json": JSON.stringify({
+                        compilerOptions: {
+                            module: "system",
+                            strictNullChecks: false
+                        },
+                        include: null, // eslint-disable-line no-null/no-null
+                        files: ["../main.ts"]
+                    }),
+                    "dev/configs/extendsArrayFifth.json": JSON.stringify({
+                        extends: ["./extendsArrayFirst", "./extendsArraySecond", "./extendsArrayThird", "./extendsArrayFourth"],
+                        files: [],
+                    }),
+                    "dev/extendsArrayFails.json": JSON.stringify({
+                        extends: ["./missingFile"],
+                        compilerOptions: {
+                            types: []
+                        }
+                    }),
+                    "dev/extendsArrayFails2.json": JSON.stringify({ extends: [42] }),
                 }
             }
         });
@@ -292,9 +332,9 @@ namespace ts {
                     messageText: `Unknown option 'excludes'. Did you mean 'exclude'?`
                 }]);
 
-                testFailure("can error when 'extends' is not a string", "extends.json", [{
+                testFailure("can error when 'extends' is not a string or Array", "extends.json", [{
                     code: 5024,
-                    messageText: `Compiler option 'extends' requires a value of type string.`
+                    messageText: `Compiler option 'extends' requires a value of type string or Array.`
                 }]);
 
                 testSuccess("can overwrite compiler options using extended 'null'", "configs/third.json", {
@@ -349,6 +389,40 @@ namespace ts {
                     assert.deepEqual(sourceFile.extendedSourceFiles, expected);
                 });
             });
+
+            describe(testName, () => {
+                it("adds extendedSourceFiles from an array only once", () => {
+                    const sourceFile = readJsonConfigFile("configs/extendsArrayFifth.json", (path) => host.readFile(path));
+                    const dir = combinePaths(basePath, "configs");
+                    const expected = [
+                        combinePaths(dir, "extendsArrayFirst.json"),
+                        combinePaths(dir, "extendsArraySecond.json"),
+                        combinePaths(dir, "extendsArrayThird.json"),
+                        combinePaths(dir, "extendsArrayFourth.json"),
+                    ];
+                    parseJsonSourceFileConfigFileContent(sourceFile, host, dir, {}, "extendsArrayFifth.json");
+                    assert.deepEqual(sourceFile.extendedSourceFiles, expected);
+                    parseJsonSourceFileConfigFileContent(sourceFile, host, dir, {}, "extendsArrayFifth.json");
+                    assert.deepEqual(sourceFile.extendedSourceFiles, expected);
+                });
+
+                testSuccess("can overwrite top-level compilerOptions", "configs/extendsArrayFifth.json", {
+                    allowJs: true,
+                    noImplicitAny: false,
+                    strictNullChecks: false,
+                    module: ModuleKind.System
+                }, []);
+
+                testFailure("can report missing configurations", "extendsArrayFails.json", [{
+                    code: 6053,
+                    messageText: `File './missingFile' not found.`
+                }]);
+
+                testFailure("can error when 'extends' is not a string or Array2", "extendsArrayFails2.json", [{
+                    code: 5024,
+                    messageText: `Compiler option 'extends' requires a value of type string.`
+                }]);
+            });
         });
     });
 }

src/testRunner/unittests/config/showConfig.ts

@@ -145,6 +145,10 @@ namespace ts {
                     }
                     break;
                 }
+                case "listOrElement": {
+                    Debug.fail();
+                    break;
+                }
                 case "string": {
                     if (option.isTSConfigOnly) {
                         args = ["-p", "tsconfig.json"];

src/testRunner/unittests/tsbuildWatch/programUpdates.ts

@@ -566,7 +566,7 @@ export function someFn() { }`),
         verifyTscWatch({
             scenario: "programUpdates",
             subScenario: "works with extended source files",
-            commandLineArgs: ["-b", "-w", "-v", "project1.tsconfig.json", "project2.tsconfig.json"],
+            commandLineArgs: ["-b", "-w", "-v", "project1.tsconfig.json", "project2.tsconfig.json", "project3.tsconfig.json"],
             sys: () => {
                 const alphaExtendedConfigFile: File = {
                     path: "/a/b/alpha.tsconfig.json",
@@ -602,10 +602,49 @@ export function someFn() { }`),
                         files: [otherFile.path]
                     })
                 };
+                const otherFile2: File = {
+                    path: "/a/b/other2.ts",
+                    content: "let k = 0;",
+                };
+                const extendsConfigFile1: File = {
+                    path: "/a/b/extendsConfig1.tsconfig.json",
+                    content: JSON.stringify({
+                        compilerOptions: {
+                            composite: true,
+                        }
+                    })
+                };
+                const extendsConfigFile2: File = {
+                    path: "/a/b/extendsConfig2.tsconfig.json",
+                    content: JSON.stringify({
+                        compilerOptions: {
+                            strictNullChecks: false,
+                        }
+                    })
+                };
+                const extendsConfigFile3: File = {
+                    path: "/a/b/extendsConfig3.tsconfig.json",
+                    content: JSON.stringify({
+                        compilerOptions: {
+                            noImplicitAny: true,
+                        }
+                    })
+                };
+                const project3Config: File = {
+                    path: "/a/b/project3.tsconfig.json",
+                    content: JSON.stringify({
+                        extends: ["./extendsConfig1.tsconfig.json", "./extendsConfig2.tsconfig.json", "./extendsConfig3.tsconfig.json"],
+                        compilerOptions: {
+                            composite: false,
+                        },
+                        files: [otherFile.path]
+                    })
+                };
                 return createWatchedSystem([
                     libFile,
                     alphaExtendedConfigFile, project1Config, commonFile1, commonFile2,
-                    bravoExtendedConfigFile, project2Config, otherFile
+                    bravoExtendedConfigFile, project2Config, otherFile, otherFile2,
+                    extendsConfigFile1, extendsConfigFile2, extendsConfigFile3, project3Config
                 ], { currentDirectory: "/a/b" });
             },
             changes: [
@@ -646,6 +685,20 @@ export function someFn() { }`),
                     change: noop,
                     timeouts: checkSingleTimeoutQueueLengthAndRunAndVerifyNoTimeout // Build project2
                 },
+                {
+                    caption: "Modify extendsConfigFile2",
+                    change: sys => sys.writeFile("/a/b/extendsConfig2.tsconfig.json", JSON.stringify({
+                        compilerOptions: { strictNullChecks: true }
+                    })),
+                    timeouts: checkSingleTimeoutQueueLengthAndRunAndVerifyNoTimeout // Build project1
+                },
+                {
+                    caption: "Modify project 3",
+                    change: sys => sys.writeFile("/a/b/project3.tsconfig.json", JSON.stringify({
+                        extends: ["./extendsConfig1.tsconfig.json", "./extendsConfig2.tsconfig.json"],
+                    })),
+                    timeouts: checkSingleTimeoutQueueLengthAndRun // Build project1
+                },
             ]
         });
 

tests/baselines/reference/api/tsserverlibrary.d.ts

@@ -4949,7 +4949,7 @@ declare namespace ts {
         /**
          * Note that the case of the config path has not yet been normalized, as no files have been imported into the project yet
          */
-        extendedConfigPath?: string;
+        extendedConfigPath?: string | string[];
     }
     export interface ExtendedConfigCacheEntry {
         extendedResult: TsConfigSourceFile;

tests/baselines/reference/api/typescript.d.ts

@@ -4949,7 +4949,7 @@ declare namespace ts {
         /**
          * Note that the case of the config path has not yet been normalized, as no files have been imported into the project yet
          */
-        extendedConfigPath?: string;
+        extendedConfigPath?: string | string[];
     }
     export interface ExtendedConfigCacheEntry {
         extendedResult: TsConfigSourceFile;