quak/test/packaging/entrypoints.test.ts

// The package manifest promises three files that only exist after a build:
// `main`, `types`, and the `quak` binary. Nothing in the test suite used to
// look at them, and `make check` runs test, lint and fmt-check but never the
// build, so `tsconfig.json` and `package.json` were free to drift apart. They
// did: `rootDir` was `./src` while `include` also pulled in `bin/**/*`, which
// is TS6059, and no build had succeeded for as long as that was true.
//
// These tests read both files and check the contract between them, without
// running a build, so they stay in the fast unit suite. The complementary
// check — that the files really landed on disk — is in `script/build`, which
// runs after the compiler and is the only place that can honestly answer it.
import { describe, expect, it } from "vitest";
import { readFileSync } from "node:fs";
import { fileURLToPath } from "node:url";
import { join, posix } from "node:path";

interface TsConfig {
    compilerOptions: {
        outDir: string;
        rootDir: string;
    };
    include: string[];
}

interface PackageJson {
    main: string;
    types: string;
    bin: Record<string, string>;
    scripts: Record<string, string>;
}

const repoRoot = fileURLToPath(new URL("../../", import.meta.url));

const readJSON = <T>(name: string): T =>
    JSON.parse(readFileSync(join(repoRoot, name), "utf-8")) as T;

const tsconfig = readJSON<TsConfig>("tsconfig.json");
const pkg = readJSON<PackageJson>("package.json");

// Paths in the two manifests are written with a leading "./"; normalize so
// they can be compared and joined. Everything here is POSIX-style because
// that is what both JSON files contain, regardless of the host OS.
const clean = (p: string): string => posix.normalize(p);
const outDir = clean(tsconfig.compilerOptions.outDir);
const rootDir = clean(tsconfig.compilerOptions.rootDir);

// The directory prefix of a glob: the part before the first segment
// containing a wildcard. "src/**/*" -> "src", "bin/**/*" -> "bin".
const globRoot = (pattern: string): string => {
    const segments = clean(pattern).split("/");
    const wildcard = segments.findIndex((s) => s.includes("*"));
    return segments.slice(0, wildcard === -1 ? segments.length : wildcard)
        .join("/") || ".";
};

// Where tsc will write the output for a source file: the path relative to
// rootDir, re-rooted under outDir, with the extension swapped.
const emitted = (source: string, extension: string): string =>
    "./" +
    posix.join(outDir, posix.relative(rootDir, clean(source))).replace(
        /\.ts$/,
        extension,
    );

describe("tsconfig include and rootDir", () => {
    // TS6059 is not a style complaint: tsc refuses to emit anything at all
    // when a compiled file sits outside rootDir, so this single mismatch
    // took out both the library and the CLI artifacts.
    it("compiles only files that live under rootDir", () => {
        for (const pattern of tsconfig.include) {
            const root = globRoot(pattern);
            const relative = posix.relative(rootDir, root);
            expect(
                relative === "" || !relative.startsWith(".."),
                `include pattern ${pattern} matches files outside rootDir ` +
                    `${rootDir}; tsc rejects that with TS6059`,
            ).toBe(true);
        }
    });
});

describe("package.json entrypoints", () => {
    // Each of these is the path a consumer resolves — `import { Client } from
    // "quak"` for main, the editor for types, `npx quak` for the bin — so a
    // wrong value is a broken package even when the build itself is green.
    it("names the file tsc emits for src/index.ts as main", () => {
        expect(pkg.main).toBe(emitted("src/index.ts", ".js"));
    });

    it("names the declaration tsc emits for src/index.ts as types", () => {
        expect(pkg.types).toBe(emitted("src/index.ts", ".d.ts"));
    });

    it("names the file tsc emits for bin/quak.ts as the quak binary", () => {
        expect(pkg.bin.quak).toBe(emitted("bin/quak.ts", ".js"));
    });

    // The README's Getting Started block tells the reader to run
    // `yarn quak login` straight after `yarn build`. That only works if a
    // `quak` script exists and points at the built CLI, not at the source.
    it("runs the built CLI from the quak script", () => {
        expect(pkg.scripts.quak).toBeDefined();
        expect(pkg.scripts.quak).toContain(pkg.bin.quak);
    });
});

describe("bin/quak.ts", () => {
    // tsc copies the shebang into the emitted file, so it has to be in the
    // source for the installed binary to be directly executable.
    it("starts with a node shebang", () => {
        const source = readFileSync(join(repoRoot, "bin/quak.ts"), "utf-8");
        expect(source.split("\n")[0]).toBe("#!/usr/bin/env node");
    });
});