clean-architecture-frontend-template/tests/unit/validated-json-artifact.test.ts

import {
  mkdtemp,
  open,
  readFile,
  readdir,
  rename,
  rm,
  writeFile,
} from "node:fs/promises";
import { tmpdir } from "node:os";
import path from "node:path";

import { afterEach, describe, expect, it } from "vitest";
import { z } from "zod";

import {
  createValidatedJsonArtifactWriter,
  writeValidatedJsonArtifact,
} from "../../scripts/lib/validated-json-artifact.ts";

const artifactSchema = z
  .object({ schemaVersion: z.literal(1), name: z.string().min(1) })
  .strict();

const temporaryDirectories: string[] = [];

async function temporaryDirectory(): Promise<string> {
  const directory = await mkdtemp(
    path.join(tmpdir(), "validated-json-artifact-"),
  );
  temporaryDirectories.push(directory);
  return directory;
}

afterEach(async () => {
  await Promise.all(
    temporaryDirectories.splice(0).map((directory) =>
      rm(directory, { force: true, recursive: true }),
    ),
  );
});

describe("validated JSON artifact writer", () => {
  it.each(["existing", "missing"] as const)(
    "rejects invalid %s artifacts before changing destination state",
    async (destinationState) => {
      const directory = await temporaryDirectory();
      const destination = path.join(directory, "artifact.json");
      if (destinationState === "existing") {
        await writeFile(destination, "previous-bytes\n", "utf8");
      }
      const entriesBefore = await readdir(directory);

      await expect(
        writeValidatedJsonArtifact({
          path: destination,
          schema: artifactSchema,
          value: { schemaVersion: 1, name: "" },
        }),
      ).rejects.toThrow();

      expect(await readdir(directory)).toEqual(entriesBefore);
      if (destinationState === "existing") {
        await expect(readFile(destination, "utf8")).resolves.toBe(
          "previous-bytes\n",
        );
      } else {
        await expect(readFile(destination, "utf8")).rejects.toMatchObject({
          code: "ENOENT",
        });
      }
    },
  );

  it("publishes complete formatted bytes through a sibling rename", async () => {
    const directory = await temporaryDirectory();
    const destination = path.join(directory, "artifact.json");

    await writeValidatedJsonArtifact({
      path: destination,
      schema: artifactSchema,
      value: { schemaVersion: 1, name: "valid" },
    });

    await expect(readFile(destination, "utf8")).resolves.toBe(
      '{\n  "schemaVersion": 1,\n  "name": "valid"\n}\n',
    );
    expect(await readdir(directory)).toEqual(["artifact.json"]);
  });

  it.each(["write", "rename"] as const)(
    "cleans only its owned sibling temp when %s fails",
    async (failurePoint) => {
      const directory = await temporaryDirectory();
      const destination = path.join(directory, "artifact.json");
      const unrelatedTemp = path.join(directory, ".artifact.json.unrelated.tmp");
      const ownedTemp = path.join(directory, ".artifact.json.owned.tmp");
      await writeFile(destination, "previous-bytes\n", "utf8");
      await writeFile(unrelatedTemp, "unrelated\n", "utf8");
      const writer = createValidatedJsonArtifactWriter({
        createNonce: () => "owned",
        fileSystem: {
          open: async (target, flags) => {
            const handle = await open(target, flags);
            return {
              writeFile: async (data, encoding) => {
                await handle.writeFile(data, encoding);
                if (failurePoint === "write") {
                  throw new Error("injected write failure");
                }
              },
              close: async () => handle.close(),
            };
          },
          rename: async (source, target) => {
            if (failurePoint === "rename") {
              throw new Error("injected rename failure");
            }
            await rename(source, target);
          },
          rm,
        },
      });

      await expect(
        writer({
          path: destination,
          schema: artifactSchema,
          value: { schemaVersion: 1, name: "valid" },
        }),
      ).rejects.toThrow(`injected ${failurePoint} failure`);

      await expect(readFile(destination, "utf8")).resolves.toBe(
        "previous-bytes\n",
      );
      await expect(readFile(unrelatedTemp, "utf8")).resolves.toBe(
        "unrelated\n",
      );
      await expect(readFile(ownedTemp, "utf8")).rejects.toMatchObject({
        code: "ENOENT",
      });
    },
  );

  it("does not delete a pre-existing colliding sibling temp", async () => {
    const directory = await temporaryDirectory();
    const destination = path.join(directory, "artifact.json");
    const collidingTemp = path.join(directory, ".artifact.json.collision.tmp");
    await writeFile(collidingTemp, "another-writer\n", "utf8");
    const writer = createValidatedJsonArtifactWriter({
      createNonce: () => "collision",
    });

    await expect(
      writer({
        path: destination,
        schema: artifactSchema,
        value: { schemaVersion: 1, name: "valid" },
      }),
    ).rejects.toMatchObject({ code: "EEXIST" });

    await expect(readFile(collidingTemp, "utf8")).resolves.toBe(
      "another-writer\n",
    );
    await expect(readFile(destination, "utf8")).rejects.toMatchObject({
      code: "ENOENT",
    });
  });
});