build.ts

#!/usr/bin/env bun
/**
 * Build script – compiles github-code-search.ts into a standalone binary.
 *
 * Usage:
 *   bun run build.ts                               # current platform
 *   bun run build.ts --target=bun-linux-x64        # cross-compile
 *
 * Supported targets (Bun executables):
 *   bun-linux-x64  bun-linux-x64-baseline  bun-linux-arm64
 *   bun-darwin-x64  bun-darwin-arm64
 *   bun-windows-x64  bun-windows-x64-baseline  bun-windows-x64-modern
 *   bun-windows-arm64
 */

import { version, description, author, license } from "./package.json" with { type: "json" };

// ─── Pure helpers (exported for unit tests) ───────────────────────────────────

export type ParsedTarget = {
  os: string;
  arch: string;
};

/**
 * Derive a canonical { os, arch } pair from a Bun target string such as
 * "bun-windows-x64-modern" or "bun-linux-arm64".
 * Returns { os: process.platform, arch: process.arch } when `t` is null/undefined.
 */
export function parseTarget(t: string | null | undefined): ParsedTarget {
  if (!t)
    return {
      // Normalize Node's "win32" platform name to the canonical "windows" used
      // throughout this build script so isWindowsTarget() / getOutfile() work
      // correctly when building natively on Windows without a --target flag.
      os: process.platform === "win32" ? "windows" : process.platform,
      arch: process.arch === "x64" ? "x64" : process.arch,
    };

  const s = t.replace(/^bun-/, "");

  if (s.startsWith("linux-x64-baseline")) return { os: "linux", arch: "x64-baseline" };
  if (s.startsWith("linux-x64")) return { os: "linux", arch: "x64" };
  if (s.startsWith("linux-arm64-musl")) return { os: "linux", arch: "arm64-musl" };
  if (s.startsWith("linux-arm64")) return { os: "linux", arch: "arm64" };
  if (s.startsWith("darwin-x64")) return { os: "darwin", arch: "x64" };
  if (s.startsWith("darwin-arm64")) return { os: "darwin", arch: "arm64" };
  if (s.startsWith("windows-x64-baseline")) return { os: "windows", arch: "x64-baseline" };
  if (s.startsWith("windows-x64-modern")) return { os: "windows", arch: "x64-modern" };
  if (s.startsWith("windows-x64")) return { os: "windows", arch: "x64" };
  if (s.startsWith("windows-arm64")) return { os: "windows", arch: "arm64" };

  // Fix: normalize win32 → windows for unrecognised target strings (e.g. future targets).
  return { os: process.platform === "win32" ? "windows" : process.platform, arch: process.arch };
}

/**
 * Returns true when the given os value targets Windows.
 */
export function isWindowsTarget(targetOs: string): boolean {
  return targetOs === "windows";
}

/**
 * Compute the output filename for the binary.
 *
 *   target=bun-linux-x64          → dist/github-code-search-linux-x64
 *   target=bun-windows-x64        → dist/github-code-search-windows-x64.exe
 *   target=bun-windows-x64-modern → dist/github-code-search-windows-x64-modern.exe
 *   target=null (native)          → dist/github-code-search
 */
export function getOutfile(targetOs: string, target: string | null): string {
  const ext = isWindowsTarget(targetOs) ? ".exe" : "";
  const suffix = target ? `-${target.replace(/^bun-/, "")}` : "";
  return `./dist/github-code-search${suffix}${ext}`;
}

export type WindowsMeta = {
  iconPath?: string;
  title?: string;
  publisher?: string;
  appVersion?: string;
  description?: string;
  copyright?: string;
};

/**
 * Build the `compile` options forwarded to Bun.build().
 * Windows binaries receive metadata-enriching flags so the resulting .exe
 * is not misidentified as "bun" by the OS and shows correct file properties.
 * See: https://bun.sh/docs/bundler/executables#windows-specific-flags
 *
 * @param meta.iconPath Absolute path to .ico — must be absolute so Bun
 *   resolves it correctly regardless of the caller's CWD.
 */
export function getBuildCompileOptions(
  targetOs: string,
  outfile: string,
  meta: WindowsMeta = {},
): NonNullable<Parameters<typeof Bun.build>[0]["compile"]> {
  if (isWindowsTarget(targetOs)) {
    return {
      outfile,
      windows: {
        // iconPath must be absolute — relative paths are resolved from the
        // process CWD which may differ from the script location.
        icon: meta.iconPath,
        // hideConsole: true — prevents Windows from spawning a detached console
        // window when the binary is launched from a GUI context (e.g. Explorer).
        // The binary still runs correctly in any terminal emulator / cmd / pwsh.
        hideConsole: true,
        title: meta.title,
        publisher: meta.publisher,
        version: meta.appVersion,
        description: meta.description,
        copyright: meta.copyright,
      },
    };
  }
  return { outfile };
}

/**
 * Extract the --target=<value> argument from a process argv array.
 * Pure function — extracted so it can be unit-tested without touching process.argv.
 */
export function parseTargetArg(argv: string[]): string | null {
  return argv.find((a) => a.startsWith("--target="))?.slice("--target=".length) ?? null;
}

/**
 * Format the human-readable version label printed during the build.
 * Pure function — extracted so it can be unit-tested.
 */
export function buildLabel(ver: string, commit: string, os: string, arch: string): string {
  return `${ver} (${commit} · ${os}/${arch})`;
}

/**
 * Format the copyright string embedded in Windows EXE metadata.
 * Pure function — extracted so it can be unit-tested.
 */
export function buildCopyrightLine(year: number, authorName: string, lic: string): string {
  return `Copyright © ${year} ${authorName} — ${lic}`;
}

// ─── CLI args ─────────────────────────────────────────────────────────────────

// Fix: guard with import.meta.main so this block does not run when build.ts is
// imported by unit tests — see issue #108.
if (import.meta.main) {
  const target = parseTargetArg(process.argv);

  // ─── Derive OS / arch from target ────────────────────────────────────────

  const { os: targetOs, arch: targetArch } = parseTarget(target);

  // ─── Output path ─────────────────────────────────────────────────────────

  const outfile = getOutfile(targetOs, target);

  // ─── Git commit hash ─────────────────────────────────────────────────────

  let commit = "dev";
  try {
    const proc = Bun.spawn(["git", "rev-parse", "--short", "HEAD"], {
      stdout: "pipe",
      stderr: "pipe",
    });
    await proc.exited;
    commit = (await new Response(proc.stdout).text()).trim() || "dev";
  } catch {
    // Not a git repo or git not available
  }

  // ─── Build ───────────────────────────────────────────────────────────────

  const label = buildLabel(version, commit, targetOs, targetArch);
  console.log(`Building github-code-search v${label}… outfile=${outfile}`);
  if (target) console.log(`  Target: ${target}`);

  // Absolute path to the Windows icon — must be absolute so Bun resolves it
  // correctly when the script is invoked from any working directory.
  const icoPath = `${import.meta.dir}/docs/public/icons/favicon.ico`;

  const currentYear = new Date().getFullYear();
  const authorName = typeof author === "string" ? author : author.name;

  await Bun.$`mkdir -p dist`;
  await Bun.build({
    entrypoints: ["./github-code-search.ts"],
    minify: true,
    // Fix: bytecode: true causes the binary to fail on Windows — removed.
    compile: getBuildCompileOptions(targetOs, outfile, {
      iconPath: icoPath,
      title: "github-code-search",
      publisher: authorName,
      appVersion: version,
      description,
      copyright: buildCopyrightLine(currentYear, authorName, license),
    }),
    define: {
      BUILD_VERSION: JSON.stringify(version),
      BUILD_COMMIT: JSON.stringify(commit),
      BUILD_TARGET_OS: JSON.stringify(targetOs),
      BUILD_TARGET_ARCH: JSON.stringify(targetArch),
    },
    target: target ? (target as Parameters<typeof Bun.build>[0]["target"]) : undefined,
  });

  console.log(`  Built ${outfile}`);

  // ─── Ad-hoc codesign (macOS only) ────────────────────────────────────────

  if (targetOs === "darwin" && process.platform === "darwin") {
    const sign = Bun.spawn(
      [
        "codesign",
        "--deep",
        "--force",
        "--sign",
        "-",
        "--entitlements",
        `${import.meta.dir}/entitlements.plist`,
        outfile,
      ],
      { stdout: "inherit", stderr: "inherit" },
    );
    const signCode = await sign.exited;
    if (signCode !== 0) {
      console.error(`codesign failed (exit ${signCode})`);
      process.exit(signCode);
    }
    console.log(`  Codesigned ${outfile}`);

    const verify = Bun.spawn(["codesign", "--verify", "--verbose", outfile], {
      stdout: "inherit",
      stderr: "inherit",
    });
    const verifyCode = await verify.exited;
    if (verifyCode !== 0) {
      console.error(`codesign verification failed (exit ${verifyCode})`);
      process.exit(verifyCode);
    }
  }
}