Adding upstream version 1.2.3.

Signed-off-by: Daniel Baumann <daniel@debian.org>

selfupdate/updater.go

@@ -0,0 +1,99 @@
+package selfupdate
+
+import (
+	"context"
+	"fmt"
+	"net/http"
+	"os"
+	"regexp"
+
+	"github.com/google/go-github/v30/github"
+	gitconfig "github.com/tcnksm/go-gitconfig"
+	"golang.org/x/oauth2"
+)
+
+// Updater is responsible for managing the context of self-update.
+// It contains GitHub client and its context.
+type Updater struct {
+	api       *github.Client
+	apiCtx    context.Context
+	validator Validator
+	filters   []*regexp.Regexp
+}
+
+// Config represents the configuration of self-update.
+type Config struct {
+	// APIToken represents GitHub API token. If it's not empty, it will be used for authentication of GitHub API
+	APIToken string
+	// EnterpriseBaseURL is a base URL of GitHub API. If you want to use this library with GitHub Enterprise,
+	// please set "https://{your-organization-address}/api/v3/" to this field.
+	EnterpriseBaseURL string
+	// EnterpriseUploadURL is a URL to upload stuffs to GitHub Enterprise instance. This is often the same as an API base URL.
+	// So if this field is not set and EnterpriseBaseURL is set, EnterpriseBaseURL is also set to this field.
+	EnterpriseUploadURL string
+	// Validator represents types which enable additional validation of downloaded release.
+	Validator Validator
+	// Filters are regexp used to filter on specific assets for releases with multiple assets.
+	// An asset is selected if it matches any of those, in addition to the regular tag, os, arch, extensions.
+	// Please make sure that your filter(s) uniquely match an asset.
+	Filters []string
+}
+
+func newHTTPClient(ctx context.Context, token string) *http.Client {
+	if token == "" {
+		return http.DefaultClient
+	}
+	src := oauth2.StaticTokenSource(&oauth2.Token{AccessToken: token})
+	return oauth2.NewClient(ctx, src)
+}
+
+// NewUpdater creates a new updater instance. It initializes GitHub API client.
+// If you set your API token to $GITHUB_TOKEN, the client will use it.
+func NewUpdater(config Config) (*Updater, error) {
+	token := config.APIToken
+	if token == "" {
+		token = os.Getenv("GITHUB_TOKEN")
+	}
+	if token == "" {
+		token, _ = gitconfig.GithubToken()
+	}
+	ctx := context.Background()
+	hc := newHTTPClient(ctx, token)
+
+	filtersRe := make([]*regexp.Regexp, 0, len(config.Filters))
+	for _, filter := range config.Filters {
+		re, err := regexp.Compile(filter)
+		if err != nil {
+			return nil, fmt.Errorf("Could not compile regular expression %q for filtering releases: %v", filter, err)
+		}
+		filtersRe = append(filtersRe, re)
+	}
+
+	if config.EnterpriseBaseURL == "" {
+		client := github.NewClient(hc)
+		return &Updater{api: client, apiCtx: ctx, validator: config.Validator, filters: filtersRe}, nil
+	}
+
+	u := config.EnterpriseUploadURL
+	if u == "" {
+		u = config.EnterpriseBaseURL
+	}
+	client, err := github.NewEnterpriseClient(config.EnterpriseBaseURL, u, hc)
+	if err != nil {
+		return nil, err
+	}
+	return &Updater{api: client, apiCtx: ctx, validator: config.Validator, filters: filtersRe}, nil
+}
+
+// DefaultUpdater creates a new updater instance with default configuration.
+// It initializes GitHub API client with default API base URL.
+// If you set your API token to $GITHUB_TOKEN, the client will use it.
+func DefaultUpdater() *Updater {
+	token := os.Getenv("GITHUB_TOKEN")
+	if token == "" {
+		token, _ = gitconfig.GithubToken()
+	}
+	ctx := context.Background()
+	client := newHTTPClient(ctx, token)
+	return &Updater{api: github.NewClient(client), apiCtx: ctx}
+}