func getBazelVersion()

in core/core.go [253:300]
31 lines of code
8 McCabe index (conditional complexity)

func getBazelVersion() (string, error) {
	// Check in this order:
	// - env var "USE_BAZEL_VERSION" is set to a specific version.
	// - env var "USE_NIGHTLY_BAZEL" or "USE_BAZEL_NIGHTLY" is set -> latest
	//   nightly. (TODO)
	// - env var "USE_CANARY_BAZEL" or "USE_BAZEL_CANARY" is set -> latest
	//   rc. (TODO)
	// - the file workspace_root/tools/bazel exists -> that version. (TODO)
	// - workspace_root/.bazeliskrc exists and contains a 'USE_BAZEL_VERSION'
	//   variable -> read contents, that version.
	// - workspace_root/.bazelversion exists -> read contents, that version.
	// - workspace_root/WORKSPACE contains a version -> that version. (TODO)
	// - fallback: latest release
	bazelVersion := GetEnvOrConfig("USE_BAZEL_VERSION")
	if len(bazelVersion) != 0 {
		return bazelVersion, nil
	}

	workingDirectory, err := os.Getwd()
	if err != nil {
		return "", fmt.Errorf("could not get working directory: %v", err)
	}

	workspaceRoot := findWorkspaceRoot(workingDirectory)
	if len(workspaceRoot) != 0 {
		bazelVersionPath := filepath.Join(workspaceRoot, ".bazelversion")
		if _, err := os.Stat(bazelVersionPath); err == nil {
			f, err := os.Open(bazelVersionPath)
			if err != nil {
				return "", fmt.Errorf("could not read %s: %v", bazelVersionPath, err)
			}
			defer f.Close()

			scanner := bufio.NewScanner(f)
			scanner.Scan()
			bazelVersion := scanner.Text()
			if err := scanner.Err(); err != nil {
				return "", fmt.Errorf("could not read version from file %s: %v", bazelVersion, err)
			}

			if len(bazelVersion) != 0 {
				return bazelVersion, nil
			}
		}
	}

	return "latest", nil
}