Tests: added support for testing against writes too

package.json

@@ -66,8 +66,10 @@
     "jest": "^29.7.0",
     "jest-snapshot-serializer-ansi": "^2.1.0",
     "jest-snapshot-serializer-raw": "^2.0.0",
+    "json-archive": "^2.1.0",
     "nanoexec": "^1.1.0",
     "prettier": "3.3.3",
+    "radix64-encoding": "^2.0.1",
     "tiny-dirname": "^1.0.1",
     "typescript": "^5.4.5"
   }

test/__tests__/cursor-offset.js

@@ -1,7 +1,7 @@
 import { runCli } from "../utils";
 
 describe("write cursorOffset to stderr with --cursor-offset <int>", () => {
-  runCli("/", [
+  runCli("", [
     "--cursor-offset",
     "2",
     "--parser",
@@ -14,7 +14,7 @@ describe("write cursorOffset to stderr with --cursor-offset <int>", () => {
 });
 
 describe("cursorOffset should not be affected by full-width character", () => {
-  runCli("/", [
+  runCli("", [
     "--cursor-offset",
     "21",
     "--parser",

test/__tests__/plugin-precedence.js

@@ -1,7 +1,7 @@
 import { runCli } from "../utils";
 
 describe("json-stringify takes precedence over json for package.json", () => {
-  runCli("/", [
+  runCli("", [
     "--stdin-filepath=package.json",
   ], {
     input:

test/utils.js

@@ -1,6 +1,10 @@
+import once from "function-once";
+import * as Archive from "json-archive";
 import exec from "nanoexec";
+import fs from "node:fs/promises";
 import path from "node:path";
 import process from "node:process";
+import Base64 from "radix64-encoding";
 
 import { expect, test } from "@jest/globals";
 import serializerRaw from "jest-snapshot-serializer-raw";
@@ -13,6 +17,48 @@ const ROOT_PATH = process.cwd();
 const BIN_PATH = path.join(ROOT_PATH, "dist", "bin.js");
 const FIXTURES_PATH = path.join(ROOT_PATH, "test", "__fixtures__");
 
+async function getArchive(folderPath) {
+  const packPrev = await Archive.pack(folderPath);
+  const archive = {
+    getPack: once(() => {
+      return Archive.pack(folderPath);
+    }),
+    getChanged: once(async () => {
+      const packNext = await archive.getPack();
+      const changed = [];
+      for (const fileName in packNext) {
+        const filePrev = packPrev[fileName];
+        const fileNext = packNext[fileName];
+        if (filePrev.contents === fileNext.contents) continue;
+        changed.push(fileName);
+      }
+      return changed;
+    }),
+    getDiff: async () => {
+      const packNext = await archive.getPack();
+      const changed = await archive.getChanged();
+      const diff = [];
+      for (const fileName of changed) {
+        const fileNext = packNext[fileName];
+        diff.push({
+          filename: fileName,
+          content: Base64.decodeStr(fileNext.contents),
+        });
+      }
+      return diff;
+    },
+    reset: async () => {
+      const changed = await archive.getChanged();
+      for (const fileName of changed) {
+        const filePath = path.join(folderPath, fileName);
+        const filePrev = packPrev[fileName];
+        await fs.writeFile(filePath, filePrev.contents, filePrev.encoding);
+      }
+    },
+  };
+  return archive;
+}
+
 function getFixturesPath(dir) {
   return path.join(FIXTURES_PATH, dir);
 }
@@ -28,6 +74,7 @@ function getNormalizedOutput(output, options) {
 
 async function runCommand(dir, args, options) {
   const cwd = getFixturesPath(dir);
+  const archive = dir ? await getArchive(cwd) : undefined;
   const result = exec("node", [BIN_PATH, ...args], { cwd, stdio: "pipe" });
 
   if (options.input) {
@@ -38,7 +85,9 @@ async function runCommand(dir, args, options) {
   const status = await result.code;
   const stdout = getNormalizedOutput((await result.stdout).toString());
   const stderr = getNormalizedOutput((await result.stderr).toString());
-  const write = []; //TODO
+  const write = (await archive?.getDiff()) || [];
+
+  await archive?.reset();
 
   return { status, stdout, stderr, write };
 }