Function AskPackageOverrideLoop

pkg/packages/packages.go:536–666

(
	packageVersionBaseline []*StepPackageVersion,
	defaultPackageVersion string, // the --package-version command line flag
	initialPackageOverrideFlags []string, // the --package command line flag (multiple occurrences)
	asker question.Asker,
	stdout io.Writer)

}

func AskPackageOverrideLoop(
	packageVersionBaseline []*StepPackageVersion,
	defaultPackageVersion string, // the --package-version command line flag
	initialPackageOverrideFlags []string, // the --package command line flag (multiple occurrences)
	asker question.Asker,
	stdout io.Writer) ([]*StepPackageVersion, []*PackageVersionOverride, error) {
	packageVersionOverrides := make([]*PackageVersionOverride, 0)

	// pickup any partial package specifications that may have arrived on the commandline
	if defaultPackageVersion != "" {
		// blind apply to everything
		packageVersionOverrides = append(packageVersionOverrides, &PackageVersionOverride{Version: defaultPackageVersion})
	}

	for _, s := range initialPackageOverrideFlags {
		ambOverride, err := ParsePackageOverrideString(s)
		if err != nil {
			continue // silently ignore anything that wasn't parseable (should we emit a warning?)
		}
		resolvedOverride, err := ResolvePackageOverride(ambOverride, packageVersionBaseline)
		if err != nil {
			continue // silently ignore anything that wasn't parseable (should we emit a warning?)
		}
		packageVersionOverrides = append(packageVersionOverrides, resolvedOverride)
	}

	overriddenPackageVersions := ApplyPackageOverrides(packageVersionBaseline, packageVersionOverrides)

outerLoop:
	for {
		err := printPackageVersions(stdout, overriddenPackageVersions)
		if err != nil {
			return nil, nil, err
		}

		// While there are any unresolved package versions, force those
		for _, pkgVersionEntry := range overriddenPackageVersions {
			if strings.TrimSpace(pkgVersionEntry.Version) == "" {

				var answer = ""
				for strings.TrimSpace(answer) == "" { // if they enter a blank line just ask again repeatedly
					err = asker(&survey.Input{
						Message: output.Yellowf("Unable to find a version for \"%s\". Specify a version:", pkgVersionEntry.PackageID),
					}, &answer, survey.WithValidator(func(ans interface{}) error {
						str, ok := ans.(string)
						if !ok {
							return errors.New("internal error; answer was not a string")
						}
						if !isValidVersion(str) {
							return fmt.Errorf("\"%s\" is not a valid version", str)
						}
						return nil
					}))

					if err != nil {
						return nil, nil, err
					}
				}