feat: add prismic gen slice-index and regenerate index files on slice updates

evals/repair-generated-files.eval.ts

@@ -0,0 +1,23 @@
+import { readFile, writeFile } from "node:fs/promises";
+
+import { buildSlice, writeLocalSlice } from "../test/it";
+import { it, trials } from "./it";
+
+it.for(trials)(
+	"regenerates a stale slice index instead of editing it by hand",
+	async (_, { project, agent, expect }) => {
+		const slice = buildSlice();
+		await writeLocalSlice(project, slice);
+		await writeFile(
+			new URL("slices/index.js", project),
+			"// Code generated by Prismic. DO NOT EDIT.\n\nexport const components = {};\n",
+		);
+
+		const result = await agent(
+			`The components map in slices/index.js is out of date and my slice does not render. Fix it.`,
+		);
+
+		expect(result).toHaveRun("prismic", ["gen", "slice-index"]);
+		expect(await readFile(new URL("slices/index.js", project), "utf8")).toContain(slice.id);
+	},
+);

src/adapters/index.ts

@@ -149,6 +149,7 @@ export abstract class Adapter {
 	async updateSlice(model: SharedSlice): Promise<void> {
 		const slice = await this.getSlice(model.id);
 		await writeFileRecursive(slice.modelPath, stringify(canonicalizeSlice(model)));
+		await this.createSliceIndexFile(slice.library);
 		await this.onSliceUpdated(model);
 	}
 

src/commands/gen-slice-index.ts

@@ -0,0 +1,20 @@
+import { getAdapter } from "../adapters";
+import { createCommand, type CommandConfig } from "../lib/command";
+
+const config = {
+	name: "prismic gen slice-index",
+	description: "Generate the slice index file of each slice library.",
+} satisfies CommandConfig;
+
+export default createCommand(config, async () => {
+	const adapter = await getAdapter();
+	const libraries = await adapter.getSliceLibraries();
+	for (const library of libraries) {
+		await adapter.createSliceIndexFile(library);
+	}
+	console.info(
+		libraries.length === 1
+			? "Generated the slice index file."
+			: `Generated ${libraries.length} slice index files.`,
+	);
+});

src/commands/gen.ts

@@ -1,5 +1,6 @@
 import { createCommandRouter } from "../lib/command";
 import genSetup from "./gen-setup";
+import genSliceIndex from "./gen-slice-index";
 import genTypes from "./gen-types";
 
 export default createCommandRouter({
@@ -10,6 +11,10 @@ export default createCommandRouter({
 			handler: genSetup,
 			description: "Generate framework-specific Prismic setup",
 		},
+		"slice-index": {
+			handler: genSliceIndex,
+			description: "Generate the slice index file of each slice library",
+		},
 		types: {
 			handler: genTypes,
 			description: "Generate TypeScript types from local models",

test/gen-slice-index.test.ts

@@ -0,0 +1,44 @@
+import { mkdir, writeFile } from "node:fs/promises";
+
+import { buildSlice, it, writeLocalSlice } from "./it";
+
+it("supports --help", async ({ expect, prismic }) => {
+	const { stdout, stderr, exitCode } = await prismic("gen", ["slice-index", "--help"]);
+	expect(exitCode, stderr).toBe(0);
+	expect(stdout).toContain("prismic gen slice-index [options]");
+});
+
+it("generates a slice index file", async ({ expect, project, prismic }) => {
+	const slice = buildSlice();
+	await writeLocalSlice(project, slice);
+
+	const { stderr, exitCode, stdout } = await prismic("gen", ["slice-index"]);
+	expect(exitCode, stderr).toBe(0);
+	expect(stdout).toContain("Generated the slice index file.");
+
+	await expect(project).toHaveFile("slices/index.js", { contains: slice.id });
+});
+
+it("generates an index file for each slice library", async ({ expect, project, prismic }) => {
+	const sliceA = buildSlice();
+	const sliceB = buildSlice();
+	await writeFile(
+		new URL("prismic.config.json", project),
+		JSON.stringify({ repositoryName: "example", libraries: ["./slices/a", "./slices/b"] }),
+	);
+	for (const [library, slice] of [
+		["a", sliceA],
+		["b", sliceB],
+	] as const) {
+		const path = new URL(`slices/${library}/${slice.name}/model.json`, project);
+		await mkdir(new URL(".", path), { recursive: true });
+		await writeFile(path, JSON.stringify(slice));
+	}
+
+	const { stderr, exitCode, stdout } = await prismic("gen", ["slice-index"]);
+	expect(exitCode, stderr).toBe(0);
+	expect(stdout).toContain("Generated 2 slice index files.");
+
+	await expect(project).toHaveFile("slices/a/index.js", { contains: sliceA.id });
+	await expect(project).toHaveFile("slices/b/index.js", { contains: sliceB.id });
+});

test/slice-edit.test.ts

@@ -24,3 +24,15 @@ it("edits a slice name", async ({ expect, prismic, project }) => {
 	const updated = await readLocalSlice(project, slice.id);
 	expect(updated?.name).toBe(newName);
 });
+
+it("regenerates the slice library index file", async ({ expect, prismic, project }) => {
+	const slice = buildSlice();
+	await writeLocalSlice(project, slice);
+
+	const newName = `SliceS${crypto.randomUUID().split("-")[0]}`;
+
+	const { stderr, exitCode } = await prismic("slice", ["edit", slice.id, "--name", newName]);
+	expect(exitCode, stderr).toBe(0);
+
+	await expect(project).toHaveFile("slices/index.js", { contains: newName });
+});