add testing and make code more easily testable

Author: rubiesonthesky

src/collectFileNames.test.ts

@@ -1,29 +1,31 @@
-import path from "node:path";
 import { describe, expect, it } from "vitest";
 
 import { collectFileNames } from "./collectFileNames.js";
 
 describe("collectFileNames", () => {
 	it("should collect files with wildcard when collection succeeds", async () => {
-		const cwd = path.resolve(import.meta.dirname, "..");
-		const fileNames = await collectFileNames(
-			path.resolve(import.meta.dirname),
-			["*"],
-		);
-		expect(fileNames).toContain(`${cwd}/src/collectFileNames.test.ts`);
+		const cwd = process.cwd();
+		const res = await collectFileNames(cwd, ["src/*"]);
+		expect(res?.fileNames).toContain(`${cwd}/src/collectFileNames.test.ts`);
+	});
+
+	it("should return undefined if includes is empty array", async () => {
+		const cwd = process.cwd();
+		const res = await collectFileNames(cwd, []);
+		expect(res).toBeUndefined();
 	});
 
 	it("should return error if node_modules are implicitly included", async () => {
-		const cwd = path.resolve(import.meta.dirname, "..");
-		const fileNames = await collectFileNames(cwd, ["*"]);
-		expect(fileNames).toEqual(
+		const cwd = process.cwd();
+		const res = await collectFileNames(cwd, ["*"]);
+		expect(res?.error).toEqual(
 			`At least one path including node_modules was included implicitly: '${cwd}/node_modules'. Either adjust TypeStat's included files to not include node_modules (recommended) or explicitly include node_modules/ (not recommended).`,
 		);
 	});
 
 	it("should NOT return error if node_modules are explicitly included", async () => {
-		const cwd = path.resolve(import.meta.dirname, "..");
-		const fileNames = await collectFileNames(cwd, ["node_modules"]);
-		expect(fileNames?.length).toBeGreaterThan(0);
+		const cwd = process.cwd();
+		const res = await collectFileNames(cwd, ["node_modules"]);
+		expect(res?.fileNames.length).toBeGreaterThan(0);
 	});
 });

src/collectFileNames.ts

@@ -1,11 +1,16 @@
 import { glob } from "node:fs/promises";
 import path from "node:path";
 
+export interface CollectFileNamesResult {
+	error?: string;
+	fileNames: readonly string[];
+}
+
 export const collectFileNames = async (
 	cwd: string,
 	include: readonly string[] | undefined,
-): Promise<readonly string[] | string | undefined> => {
-	if (include === undefined) {
+): Promise<CollectFileNamesResult | undefined> => {
+	if (!include?.length) {
 		return undefined;
 	}
 
@@ -16,10 +21,13 @@ export const collectFileNames = async (
 	);
 
 	if (implicitNodeModulesInclude) {
-		return `At least one path including node_modules was included implicitly: '${implicitNodeModulesInclude}'. Either adjust TypeStat's included files to not include node_modules (recommended) or explicitly include node_modules/ (not recommended).`;
+		return {
+			error: `At least one path including node_modules was included implicitly: '${implicitNodeModulesInclude}'. Either adjust TypeStat's included files to not include node_modules (recommended) or explicitly include node_modules/ (not recommended).`,
+			fileNames: [],
+		};
 	}
 
-	return fileNames;
+	return { fileNames };
 };
 
 const collectFileNamesFromGlobs = async (
@@ -36,9 +44,9 @@ const collectFileNamesFromGlobs = async (
 const implicitNodeModulesIncluded = (
 	fileGlobs: readonly string[],
 	fileNames: readonly string[],
-): boolean => {
-	return (
-		!fileGlobs.some((glob) => glob.includes("node_modules")) &&
-		fileNames.some((fileName) => fileName.includes("node_modules"))
-	);
+): string | undefined => {
+	if (fileGlobs.some((glob) => glob.includes("node_modules"))) {
+		return undefined;
+	}
+	return fileNames.find((fileName) => fileName.includes("node_modules"));
 };

src/index.ts

@@ -91,11 +91,14 @@ export const typeStat = async (
 
 	for (let i = 0; i < allPendingOptions.length; i += 1) {
 		// Collect all files to be run on this option iteration from the include glob(s)
-		const fileNames = await collectFileNames(cwd, allPendingOptions[i].include);
-		if (typeof fileNames !== "object") {
+		const fileNamesRes = await collectFileNames(
+			cwd,
+			allPendingOptions[i].include,
+		);
+		if (!fileNamesRes || fileNamesRes.error) {
 			return {
 				error: new Error(
-					`Could not run options object ${i + 1}: ${fileNames ?? `No files included by the 'include' setting were found.`}`,
+					`Could not run options object ${i + 1}: ${fileNamesRes?.error ?? `No files included by the 'include' setting were found.`}`,
 				),
 				status: ResultStatus.Failed,
 			};
@@ -116,7 +119,7 @@ export const typeStat = async (
 			await runMutations({
 				mutationsProvider: createTypeStatProvider({
 					...allPendingOptions[i],
-					fileNames,
+					fileNames: fileNamesRes.fileNames,
 				}),
 			});
 		} catch (error) {

…lization/initializeProject/index.spec.ts …lization/initializeProject/index.test.tssrc/initialization/initializeProject/index.spec.ts renamed to src/initialization/initializeProject/index.test.ts src/initialization/initializeProject/index.spec.ts renamed to src/initialization/initializeProject/index.test.ts

@@ -0,0 +1,22 @@
+import { describe, expect, it } from "vitest";
+
+import { getFixImportExtensionsMutations } from "./index.js";
+
+describe("getFixImportExtensionsMutations", () => {
+	it("should collect list of tsconfig files", () => {
+		const mutations = getFixImportExtensionsMutations(
+			process.cwd() + "/src/mutators/builtIn/fixImportExtensions/index.ts",
+			"./README",
+			1,
+		);
+		expect(mutations).toMatchInlineSnapshot(`
+			{
+			  "insertion": ".md",
+			  "range": {
+			    "begin": 0,
+			  },
+			  "type": "text-insert",
+			}
+		`);
+	});
+});

src/mutators/builtIn/fixImportExtensions/index.test.ts

@@ -50,11 +50,20 @@ const visitExportOrImportDeclaration = (
 		return undefined;
 	}
 
-	// Try each path that the import could resolve to
-	const basePath = path.join(
-		path.dirname(request.sourceFile.fileName),
+	return getFixImportExtensionsMutations(
+		request.sourceFile.fileName,
 		node.moduleSpecifier.text,
+		node.moduleSpecifier.end,
 	);
+};
+
+export const getFixImportExtensionsMutations = (
+	sourceFileName: string,
+	moduleSpecifier: string,
+	end: number,
+): TextInsertMutation | undefined => {
+	// Try each path that the import could resolve to
+	const basePath = path.join(path.dirname(sourceFileName), moduleSpecifier);
 
 	for (const filePath of [basePath, path.join(basePath, "index")]) {
 		// If no files exist under that path, ignore this possibility
@@ -75,7 +84,7 @@ const visitExportOrImportDeclaration = (
 		return {
 			insertion: "." + path.basename(mostLikely).split(".").slice(1).join("."),
 			range: {
-				begin: node.moduleSpecifier.end - 1,
+				begin: end - 1,
 			},
 			type: "text-insert",
 		};