func loadLocalModule()

in cmd/gorelease/gorelease.go [295:438]
109 lines of code
31 McCabe index (conditional complexity)

func loadLocalModule(ctx context.Context, modRoot, repoRoot, version string) (m moduleInfo, err error) {
	if repoRoot != "" && !hasFilePathPrefix(modRoot, repoRoot) {
		return moduleInfo{}, fmt.Errorf("module root %q is not in repository root %q", modRoot, repoRoot)
	}

	// Load the go.mod file and check the module path and go version.
	m = moduleInfo{
		modRoot:   modRoot,
		repoRoot:  repoRoot,
		version:   version,
		goModPath: filepath.Join(modRoot, "go.mod"),
	}

	if version != "" && semver.Compare(version, "v0.0.0-99999999999999-zzzzzzzzzzzz") < 0 {
		m.diagnostics = append(m.diagnostics, fmt.Sprintf("Version %s is lower than most pseudo-versions. Consider releasing v0.1.0-0 instead.", version))
	}

	m.goModData, err = ioutil.ReadFile(m.goModPath)
	if err != nil {
		return moduleInfo{}, err
	}
	m.goModFile, err = modfile.ParseLax(m.goModPath, m.goModData, nil)
	if err != nil {
		return moduleInfo{}, err
	}
	if m.goModFile.Module == nil {
		return moduleInfo{}, fmt.Errorf("%s: module directive is missing", m.goModPath)
	}
	m.modPath = m.goModFile.Module.Mod.Path
	if err := checkModPath(m.modPath); err != nil {
		return moduleInfo{}, err
	}
	var ok bool
	_, m.modPathMajor, ok = module.SplitPathVersion(m.modPath)
	if !ok {
		// we just validated the path above.
		panic(fmt.Sprintf("could not find version suffix in module path %q", m.modPath))
	}
	if m.goModFile.Go == nil {
		m.diagnostics = append(m.diagnostics, "go.mod: go directive is missing")
	}

	// Determine the version tag prefix for the module within the repository.
	if repoRoot != "" && modRoot != repoRoot {
		if strings.HasPrefix(m.modPathMajor, ".") {
			m.diagnostics = append(m.diagnostics, fmt.Sprintf("%s: module path starts with gopkg.in and must be declared in the root directory of the repository", m.modPath))
		} else {
			codeDir := filepath.ToSlash(modRoot[len(repoRoot)+1:])
			var altGoModPath string
			if m.modPathMajor == "" {
				// module has no major version suffix.
				// codeDir must be a suffix of modPath.
				// tagPrefix is codeDir with a trailing slash.
				if strings.HasSuffix(m.modPath, "/"+codeDir) {
					m.tagPrefix = codeDir + "/"
				} else {
					m.diagnostics = append(m.diagnostics, fmt.Sprintf("%s: module path must end with %[2]q, since it is in subdirectory %[2]q", m.modPath, codeDir))
				}
			} else {
				if strings.HasSuffix(m.modPath, "/"+codeDir) {
					// module has a major version suffix and is in a major version subdirectory.
					// codeDir must be a suffix of modPath.
					// tagPrefix must not include the major version.
					m.tagPrefix = codeDir[:len(codeDir)-len(m.modPathMajor)+1]
					altGoModPath = modRoot[:len(modRoot)-len(m.modPathMajor)+1] + "go.mod"
				} else if strings.HasSuffix(m.modPath, "/"+codeDir+m.modPathMajor) {
					// module has a major version suffix and is not in a major version subdirectory.
					// codeDir + modPathMajor is a suffix of modPath.
					// tagPrefix is codeDir with a trailing slash.
					m.tagPrefix = codeDir + "/"
					altGoModPath = filepath.Join(modRoot, m.modPathMajor[1:], "go.mod")
				} else {
					m.diagnostics = append(m.diagnostics, fmt.Sprintf("%s: module path must end with %[2]q or %q, since it is in subdirectory %[2]q", m.modPath, codeDir, codeDir+m.modPathMajor))
				}
			}

			// Modules with major version suffixes can be defined in two places
			// (e.g., sub/go.mod and sub/v2/go.mod). They must not be defined in both.
			if altGoModPath != "" {
				if data, err := ioutil.ReadFile(altGoModPath); err == nil {
					if altModPath := modfile.ModulePath(data); m.modPath == altModPath {
						goModRel, _ := filepath.Rel(repoRoot, m.goModPath)
						altGoModRel, _ := filepath.Rel(repoRoot, altGoModPath)
						m.diagnostics = append(m.diagnostics, fmt.Sprintf("module is defined in two locations:\n\t%s\n\t%s", goModRel, altGoModRel))
					}
				}
			}
		}
	}

	// Load the module's packages.
	// We pack the module into a zip file and extract it to a temporary directory
	// as if it were published and downloaded. We'll detect any errors that would
	// occur (for example, invalid file names). We avoid loading it as the
	// main module.
	tmpModRoot, err := copyModuleToTempDir(repoRoot, m.modPath, m.modRoot)
	if err != nil {
		return moduleInfo{}, err
	}
	defer func() {
		if rerr := os.RemoveAll(tmpModRoot); err == nil && rerr != nil {
			err = fmt.Errorf("removing temporary module directory: %v", rerr)
		}
	}()
	tmpLoadDir, tmpGoModData, tmpGoSumData, pkgPaths, prepareDiagnostics, err := prepareLoadDir(ctx, m.goModFile, m.modPath, tmpModRoot, version, false)
	if err != nil {
		return moduleInfo{}, err
	}
	defer func() {
		if rerr := os.RemoveAll(tmpLoadDir); err == nil && rerr != nil {
			err = fmt.Errorf("removing temporary load directory: %v", rerr)
		}
	}()

	var loadDiagnostics []string
	m.pkgs, loadDiagnostics, err = loadPackages(ctx, m.modPath, tmpModRoot, tmpLoadDir, tmpGoModData, tmpGoSumData, pkgPaths)
	if err != nil {
		return moduleInfo{}, err
	}

	m.diagnostics = append(m.diagnostics, prepareDiagnostics...)
	m.diagnostics = append(m.diagnostics, loadDiagnostics...)

	highestVersion, err := findSelectedVersion(ctx, tmpLoadDir, m.modPath)
	if err != nil {
		return moduleInfo{}, err
	}

	if highestVersion != "" {
		// A version of the module is included in the transitive dependencies.
		// Add it to the moduleInfo so that the release report stage can use it
		// in verifying the version or suggestion a new version, depending on
		// whether the user provided a version already.
		m.highestTransitiveVersion = highestVersion
	}

	retracted, err := loadRetractions(ctx, tmpLoadDir)
	if err != nil {
		return moduleInfo{}, err
	}
	m.diagnostics = append(m.diagnostics, retracted...)

	return m, nil
}