[templating] Refactor: Move twitch functions into library package

Signed-off-by: Knut Ahlers <knut@ahlers.me>

docs/content/configuration/templating.md

@@ -389,7 +389,7 @@ Example:
 
 ```
 # Your int this hour: {{ printf "%.0f" (mulf (seededRandom (list "int" .username (now | date "2006-01-02 15") | join ":")) 100) }}%
-< Your int this hour: 77%
+< Your int this hour: 46%
 ```
 
 ### `streamUptime`

functions_twitch.go

@@ -1,254 +0,0 @@
-package main
-
-import (
-	"context"
-	"strings"
-	"time"
-
-	"github.com/pkg/errors"
-
-	"github.com/Luzifer/twitch-bot/v3/internal/service/access"
-	"github.com/Luzifer/twitch-bot/v3/pkg/twitch"
-	"github.com/Luzifer/twitch-bot/v3/plugins"
-)
-
-//nolint:funlen
-func init() {
-	tplFuncs.Register("displayName", plugins.GenericTemplateFunctionGetter(tplTwitchDisplayName), plugins.TemplateFuncDocumentation{
-		Description: "Returns the display name the specified user set for themselves",
-		Syntax:      "displayName <username> [fallback]",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ displayName "luziferus" }} - {{ displayName "notexistinguser" "foobar" }}`,
-			FakedOutput: "Luziferus - foobar",
-		},
-	})
-
-	tplFuncs.Register("doesFollowLongerThan", plugins.GenericTemplateFunctionGetter(tplTwitchDoesFollowLongerThan), plugins.TemplateFuncDocumentation{
-		Description: "Returns whether `from` follows `to` for more than `duration`",
-		Syntax:      "doesFollowLongerThan <from> <to> <duration>",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ doesFollowLongerThan "tezrian" "luziferus" "168h" }}`,
-			FakedOutput: "true",
-		},
-	})
-
-	tplFuncs.Register("doesFollow", plugins.GenericTemplateFunctionGetter(tplTwitchDoesFollow), plugins.TemplateFuncDocumentation{
-		Description: "Returns whether `from` follows `to`",
-		Syntax:      "doesFollow <from> <to>",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ doesFollow "tezrian" "luziferus" }}`,
-			FakedOutput: "true",
-		},
-	})
-
-	tplFuncs.Register("followAge", plugins.GenericTemplateFunctionGetter(tplTwitchFollowAge), plugins.TemplateFuncDocumentation{
-		Description: "Looks up when `from` followed `to` and returns the duration between then and now",
-		Syntax:      "followAge <from> <to>",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ followAge "tezrian" "luziferus" }}`,
-			FakedOutput: "15004h14m59.116620989s",
-		},
-	})
-
-	tplFuncs.Register("followDate", plugins.GenericTemplateFunctionGetter(tplTwitchFollowDate), plugins.TemplateFuncDocumentation{
-		Description: "Looks up when `from` followed `to`",
-		Syntax:      "followDate <from> <to>",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ followDate "tezrian" "luziferus" }}`,
-			FakedOutput: "2021-04-10 16:07:07 +0000 UTC",
-		},
-	})
-
-	tplFuncs.Register("idForUsername", plugins.GenericTemplateFunctionGetter(tplTwitchIDForUsername), plugins.TemplateFuncDocumentation{
-		Description: "Returns the user-id for the given username",
-		Syntax:      "idForUsername <username>",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ idForUsername "twitch" }}`,
-			FakedOutput: "12826",
-		},
-	})
-
-	tplFuncs.Register("lastPoll", plugins.GenericTemplateFunctionGetter(tplTwitchLastPoll), plugins.TemplateFuncDocumentation{
-		Description: "Gets the last (currently running or archived) poll for the given channel (the channel must have given extended permission for poll access!)",
-		Syntax:      "lastPoll <channel>",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `Last Poll: {{ (lastPoll .channel).Title }}`,
-			FakedOutput: "Last Poll: Und wie siehts im Template aus?",
-		},
-		Remarks: "See schema of returned object in [`pkg/twitch/polls.go#L13`](https://github.com/Luzifer/twitch-bot/blob/master/pkg/twitch/polls.go#L13)",
-	})
-
-	tplFuncs.Register("profileImage", plugins.GenericTemplateFunctionGetter(tplTwitchProfileImage), plugins.TemplateFuncDocumentation{
-		Description: "Gets the URL of the given users profile image",
-		Syntax:      "profileImage <username>",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ profileImage .username }}`,
-			FakedOutput: "https://static-cdn.jtvnw.net/jtv_user_pictures/[...].png",
-		},
-	})
-
-	tplFuncs.Register("recentGame", plugins.GenericTemplateFunctionGetter(tplTwitchRecentGame), plugins.TemplateFuncDocumentation{
-		Description: "Returns the last played game name of the specified user (see shoutout example) or the `fallback` if the game could not be fetched. If no fallback was supplied the message will fail and not be sent.",
-		Syntax:      "recentGame <username> [fallback]",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ recentGame "luziferus" "none" }} - {{ recentGame "thisuserdoesnotexist123" "none" }}`,
-			FakedOutput: "Metro Exodus - none",
-		},
-	})
-
-	tplFuncs.Register("recentTitle", plugins.GenericTemplateFunctionGetter(tplTwitchRecentTitle), plugins.TemplateFuncDocumentation{
-		Description: "Returns the last stream title of the specified user or the `fallback` if the title could not be fetched. If no fallback was supplied the message will fail and not be sent.",
-		Syntax:      "recentTitle <username> [fallback]",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ recentGame "luziferus" "none" }} - {{ recentGame "thisuserdoesnotexist123" "none" }}`,
-			FakedOutput: "Die Oper haben wir überlebt, mal sehen was uns sonst noch alles töten möchte… - none",
-		},
-	})
-
-	tplFuncs.Register("streamUptime", plugins.GenericTemplateFunctionGetter(tplTwitchStreamUptime), plugins.TemplateFuncDocumentation{
-		Description: "Returns the duration the stream is online (causes an error if no current stream is found)",
-		Syntax:      "streamUptime <username>",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ formatDuration (streamUptime "luziferus") "hours" "minutes" "" }}`,
-			FakedOutput: "3 hours, 56 minutes",
-		},
-	})
-
-	tplFuncs.Register("usernameForID", plugins.GenericTemplateFunctionGetter(tplTwitchUsernameForID), plugins.TemplateFuncDocumentation{
-		Description: "Returns the current login name of an user-id",
-		Syntax:      "usernameForID <user-id>",
-		Example: &plugins.TemplateFuncDocumentationExample{
-			Template:    `{{ usernameForID "12826" }}`,
-			FakedOutput: "twitch",
-		},
-	})
-}
-
-func tplTwitchDisplayName(username string, v ...string) (string, error) {
-	displayName, err := twitchClient.GetDisplayNameForUser(strings.TrimLeft(username, "#"))
-	if len(v) > 0 && (err != nil || displayName == "") {
-		return v[0], nil //nolint:nilerr // Default value, no need to return error
-	}
-
-	return displayName, err
-}
-
-func tplTwitchDoesFollow(from, to string) (bool, error) {
-	_, err := twitchClient.GetFollowDate(from, to)
-	switch {
-	case err == nil:
-		return true, nil
-
-	case errors.Is(err, twitch.ErrUserDoesNotFollow):
-		return false, nil
-
-	default:
-		return false, errors.Wrap(err, "getting follow date")
-	}
-}
-
-func tplTwitchFollowAge(from, to string) (time.Duration, error) {
-	since, err := twitchClient.GetFollowDate(from, to)
-	return time.Since(since), errors.Wrap(err, "getting follow date")
-}
-
-func tplTwitchFollowDate(from, to string) (time.Time, error) {
-	return twitchClient.GetFollowDate(from, to)
-}
-
-func tplTwitchDoesFollowLongerThan(from, to string, t any) (bool, error) {
-	var (
-		age time.Duration
-		err error
-	)
-
-	switch v := t.(type) {
-	case int64:
-		age = time.Duration(v) * time.Second
-
-	case string:
-		if age, err = time.ParseDuration(v); err != nil {
-			return false, errors.Wrap(err, "parsing duration")
-		}
-
-	default:
-		return false, errors.Errorf("unexpected input for duration %t", t)
-	}
-
-	fd, err := twitchClient.GetFollowDate(from, to)
-	switch {
-	case err == nil:
-		return time.Since(fd) > age, nil
-
-	case errors.Is(err, twitch.ErrUserDoesNotFollow):
-		return false, nil
-
-	default:
-		return false, errors.Wrap(err, "getting follow date")
-	}
-}
-
-func tplTwitchIDForUsername(username string) (string, error) {
-	return twitchClient.GetIDForUsername(username)
-}
-
-func tplTwitchLastPoll(username string) (*twitch.PollInfo, error) {
-	hasPollAccess, err := accessService.HasAnyPermissionForChannel(username, twitch.ScopeChannelReadPolls, twitch.ScopeChannelManagePolls)
-	if err != nil {
-		return nil, errors.Wrap(err, "checking read-poll-permission")
-	}
-
-	if !hasPollAccess {
-		return nil, errors.Errorf("not authorized to read polls for channel %s", username)
-	}
-
-	tc, err := accessService.GetTwitchClientForChannel(strings.TrimLeft(username, "#"), access.ClientConfig{
-		TwitchClient:       cfg.TwitchClient,
-		TwitchClientSecret: cfg.TwitchClientSecret,
-	})
-	if err != nil {
-		return nil, errors.Wrap(err, "getting twitch client for user")
-	}
-
-	poll, err := tc.GetLatestPoll(context.Background(), strings.TrimLeft(username, "#"))
-	return poll, errors.Wrap(err, "getting last poll")
-}
-
-func tplTwitchProfileImage(username string) (string, error) {
-	user, err := twitchClient.GetUserInformation(strings.TrimLeft(username, "#@"))
-	if err != nil {
-		return "", errors.Wrap(err, "getting user info")
-	}
-
-	return user.ProfileImageURL, nil
-}
-
-func tplTwitchRecentGame(username string, v ...string) (string, error) {
-	game, _, err := twitchClient.GetRecentStreamInfo(strings.TrimLeft(username, "#"))
-	if len(v) > 0 && (err != nil || game == "") {
-		return v[0], nil
-	}
-
-	return game, err
-}
-
-func tplTwitchRecentTitle(username string, v ...string) (string, error) {
-	_, title, err := twitchClient.GetRecentStreamInfo(strings.TrimLeft(username, "#"))
-	if len(v) > 0 && (err != nil || title == "") {
-		return v[0], nil
-	}
-
-	return title, err
-}
-
-func tplTwitchStreamUptime(username string) (time.Duration, error) {
-	si, err := twitchClient.GetCurrentStreamInfo(strings.TrimLeft(username, "#"))
-	if err != nil {
-		return 0, err
-	}
-	return time.Since(si.StartedAt), nil
-}
-
-func tplTwitchUsernameForID(id string) (string, error) {
-	return twitchClient.GetUsernameForID(context.Background(), id)
-}

internal/template/twitch/follow.go

@@ -0,0 +1,110 @@
+package twitch
+
+import (
+	"time"
+
+	"github.com/Luzifer/twitch-bot/v3/pkg/twitch"
+	"github.com/Luzifer/twitch-bot/v3/plugins"
+	"github.com/pkg/errors"
+)
+
+func init() {
+	regFn = append(
+		regFn,
+		tplTwitchDoesFollow,
+		tplTwitchDoesFollowLongerThan,
+		tplTwitchFollowAge,
+		tplTwitchFollowDate,
+	)
+}
+
+func tplTwitchDoesFollowLongerThan(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("doesFollowLongerThan", plugins.GenericTemplateFunctionGetter(func(from, to string, t any) (bool, error) {
+		var (
+			age time.Duration
+			err error
+		)
+
+		switch v := t.(type) {
+		case int64:
+			age = time.Duration(v) * time.Second
+
+		case string:
+			if age, err = time.ParseDuration(v); err != nil {
+				return false, errors.Wrap(err, "parsing duration")
+			}
+
+		default:
+			return false, errors.Errorf("unexpected input for duration %t", t)
+		}
+
+		fd, err := args.GetTwitchClient().GetFollowDate(from, to)
+		switch {
+		case err == nil:
+			return time.Since(fd) > age, nil
+
+		case errors.Is(err, twitch.ErrUserDoesNotFollow):
+			return false, nil
+
+		default:
+			return false, errors.Wrap(err, "getting follow date")
+		}
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Returns whether `from` follows `to` for more than `duration`",
+		Syntax:      "doesFollowLongerThan <from> <to> <duration>",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ doesFollowLongerThan "tezrian" "luziferus" "168h" }}`,
+			FakedOutput: "true",
+		},
+	})
+}
+
+func tplTwitchDoesFollow(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("doesFollow", plugins.GenericTemplateFunctionGetter(func(from, to string) (bool, error) {
+		_, err := args.GetTwitchClient().GetFollowDate(from, to)
+		switch {
+		case err == nil:
+			return true, nil
+
+		case errors.Is(err, twitch.ErrUserDoesNotFollow):
+			return false, nil
+
+		default:
+			return false, errors.Wrap(err, "getting follow date")
+		}
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Returns whether `from` follows `to`",
+		Syntax:      "doesFollow <from> <to>",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ doesFollow "tezrian" "luziferus" }}`,
+			FakedOutput: "true",
+		},
+	})
+}
+
+func tplTwitchFollowAge(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("followAge", plugins.GenericTemplateFunctionGetter(func(from, to string) (time.Duration, error) {
+		since, err := args.GetTwitchClient().GetFollowDate(from, to)
+		return time.Since(since), errors.Wrap(err, "getting follow date")
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Looks up when `from` followed `to` and returns the duration between then and now",
+		Syntax:      "followAge <from> <to>",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ followAge "tezrian" "luziferus" }}`,
+			FakedOutput: "15004h14m59.116620989s",
+		},
+	})
+}
+
+func tplTwitchFollowDate(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("followDate", plugins.GenericTemplateFunctionGetter(func(from, to string) (time.Time, error) {
+		return args.GetTwitchClient().GetFollowDate(from, to)
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Looks up when `from` followed `to`",
+		Syntax:      "followDate <from> <to>",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ followDate "tezrian" "luziferus" }}`,
+			FakedOutput: "2021-04-10 16:07:07 +0000 UTC",
+		},
+	})
+}

internal/template/twitch/poll.go

@@ -0,0 +1,46 @@
+package twitch
+
+import (
+	"context"
+	"strings"
+
+	"github.com/Luzifer/twitch-bot/v3/pkg/twitch"
+	"github.com/Luzifer/twitch-bot/v3/plugins"
+	"github.com/pkg/errors"
+)
+
+func init() {
+	regFn = append(
+		regFn,
+		tplTwitchLastPoll,
+	)
+}
+
+func tplTwitchLastPoll(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("lastPoll", plugins.GenericTemplateFunctionGetter(func(username string) (*twitch.PollInfo, error) {
+		hasPollAccess, err := args.HasAnyPermissionForChannel(username, twitch.ScopeChannelReadPolls, twitch.ScopeChannelManagePolls)
+		if err != nil {
+			return nil, errors.Wrap(err, "checking read-poll-permission")
+		}
+
+		if !hasPollAccess {
+			return nil, errors.Errorf("not authorized to read polls for channel %s", username)
+		}
+
+		tc, err := args.GetTwitchClientForChannel(strings.TrimLeft(username, "#"))
+		if err != nil {
+			return nil, errors.Wrap(err, "getting twitch client for user")
+		}
+
+		poll, err := tc.GetLatestPoll(context.Background(), strings.TrimLeft(username, "#"))
+		return poll, errors.Wrap(err, "getting last poll")
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Gets the last (currently running or archived) poll for the given channel (the channel must have given extended permission for poll access!)",
+		Syntax:      "lastPoll <channel>",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `Last Poll: {{ (lastPoll .channel).Title }}`,
+			FakedOutput: "Last Poll: Und wie siehts im Template aus?",
+		},
+		Remarks: "See schema of returned object in [`pkg/twitch/polls.go#L13`](https://github.com/Luzifer/twitch-bot/blob/master/pkg/twitch/polls.go#L13)",
+	})
+}

internal/template/twitch/stream.go

@@ -0,0 +1,70 @@
+package twitch
+
+import (
+	"strings"
+	"time"
+
+	"github.com/Luzifer/twitch-bot/v3/plugins"
+)
+
+func init() {
+	regFn = append(
+		regFn,
+		tplTwitchRecentGame,
+		tplTwitchRecentTitle,
+		tplTwitchStreamUptime,
+	)
+}
+
+func tplTwitchRecentGame(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("recentGame", plugins.GenericTemplateFunctionGetter(func(username string, v ...string) (string, error) {
+		game, _, err := args.GetTwitchClient().GetRecentStreamInfo(strings.TrimLeft(username, "#"))
+		if len(v) > 0 && (err != nil || game == "") {
+			return v[0], nil
+		}
+
+		return game, err
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Returns the last played game name of the specified user (see shoutout example) or the `fallback` if the game could not be fetched. If no fallback was supplied the message will fail and not be sent.",
+		Syntax:      "recentGame <username> [fallback]",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ recentGame "luziferus" "none" }} - {{ recentGame "thisuserdoesnotexist123" "none" }}`,
+			FakedOutput: "Metro Exodus - none",
+		},
+	})
+}
+
+func tplTwitchRecentTitle(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("recentTitle", plugins.GenericTemplateFunctionGetter(func(username string, v ...string) (string, error) {
+		_, title, err := args.GetTwitchClient().GetRecentStreamInfo(strings.TrimLeft(username, "#"))
+		if len(v) > 0 && (err != nil || title == "") {
+			return v[0], nil
+		}
+
+		return title, err
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Returns the last stream title of the specified user or the `fallback` if the title could not be fetched. If no fallback was supplied the message will fail and not be sent.",
+		Syntax:      "recentTitle <username> [fallback]",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ recentGame "luziferus" "none" }} - {{ recentGame "thisuserdoesnotexist123" "none" }}`,
+			FakedOutput: "Die Oper haben wir überlebt, mal sehen was uns sonst noch alles töten möchte… - none",
+		},
+	})
+}
+
+func tplTwitchStreamUptime(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("streamUptime", plugins.GenericTemplateFunctionGetter(func(username string) (time.Duration, error) {
+		si, err := args.GetTwitchClient().GetCurrentStreamInfo(strings.TrimLeft(username, "#"))
+		if err != nil {
+			return 0, err
+		}
+		return time.Since(si.StartedAt), nil
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Returns the duration the stream is online (causes an error if no current stream is found)",
+		Syntax:      "streamUptime <username>",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ formatDuration (streamUptime "luziferus") "hours" "minutes" "" }}`,
+			FakedOutput: "3 hours, 56 minutes",
+		},
+	})
+}

internal/template/twitch/twitch.go

@@ -0,0 +1,17 @@
+// Package twitch defines Twitch related template functions not having
+// their place in any other package
+package twitch
+
+import (
+	"github.com/Luzifer/twitch-bot/v3/plugins"
+)
+
+var regFn []func(plugins.RegistrationArguments)
+
+func Register(args plugins.RegistrationArguments) error {
+	for _, fn := range regFn {
+		fn(args)
+	}
+
+	return nil
+}

internal/template/twitch/user.go

@@ -0,0 +1,81 @@
+package twitch
+
+import (
+	"context"
+	"strings"
+
+	"github.com/Luzifer/twitch-bot/v3/plugins"
+	"github.com/pkg/errors"
+)
+
+func init() {
+	regFn = append(
+		regFn,
+		tplTwitchDisplayName,
+		tplTwitchIDForUsername,
+		tplTwitchProfileImage,
+		tplTwitchUsernameForID,
+	)
+}
+
+func tplTwitchDisplayName(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("displayName", plugins.GenericTemplateFunctionGetter(func(username string, v ...string) (string, error) {
+		displayName, err := args.GetTwitchClient().GetDisplayNameForUser(strings.TrimLeft(username, "#"))
+		if len(v) > 0 && (err != nil || displayName == "") {
+			return v[0], nil //nolint:nilerr // Default value, no need to return error
+		}
+
+		return displayName, err
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Returns the display name the specified user set for themselves",
+		Syntax:      "displayName <username> [fallback]",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ displayName "luziferus" }} - {{ displayName "notexistinguser" "foobar" }}`,
+			FakedOutput: "Luziferus - foobar",
+		},
+	})
+}
+
+func tplTwitchIDForUsername(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("idForUsername", plugins.GenericTemplateFunctionGetter(func(username string) (string, error) {
+		return args.GetTwitchClient().GetIDForUsername(username)
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Returns the user-id for the given username",
+		Syntax:      "idForUsername <username>",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ idForUsername "twitch" }}`,
+			FakedOutput: "12826",
+		},
+	})
+}
+
+func tplTwitchProfileImage(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("profileImage", plugins.GenericTemplateFunctionGetter(func(username string) (string, error) {
+		user, err := args.GetTwitchClient().GetUserInformation(strings.TrimLeft(username, "#@"))
+		if err != nil {
+			return "", errors.Wrap(err, "getting user info")
+		}
+
+		return user.ProfileImageURL, nil
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Gets the URL of the given users profile image",
+		Syntax:      "profileImage <username>",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ profileImage .username }}`,
+			FakedOutput: "https://static-cdn.jtvnw.net/jtv_user_pictures/[...].png",
+		},
+	})
+}
+
+func tplTwitchUsernameForID(args plugins.RegistrationArguments) {
+	args.RegisterTemplateFunction("usernameForID", plugins.GenericTemplateFunctionGetter(func(id string) (string, error) {
+		return args.GetTwitchClient().GetUsernameForID(context.Background(), id)
+	}), plugins.TemplateFuncDocumentation{
+		Description: "Returns the current login name of an user-id",
+		Syntax:      "usernameForID <user-id>",
+		Example: &plugins.TemplateFuncDocumentationExample{
+			Template:    `{{ usernameForID "12826" }}`,
+			FakedOutput: "twitch",
+		},
+	})
+}

plugins_core.go

@@ -48,6 +48,7 @@ import (
 	"github.com/Luzifer/twitch-bot/v3/internal/template/slice"
 	"github.com/Luzifer/twitch-bot/v3/internal/template/strings"
 	"github.com/Luzifer/twitch-bot/v3/internal/template/subscriber"
+	twitchFns "github.com/Luzifer/twitch-bot/v3/internal/template/twitch"
 	"github.com/Luzifer/twitch-bot/v3/pkg/database"
 	"github.com/Luzifer/twitch-bot/v3/pkg/twitch"
 	"github.com/Luzifer/twitch-bot/v3/plugins"
@@ -93,6 +94,7 @@ var (
 		slice.Register,
 		strings.Register,
 		subscriber.Register,
+		twitchFns.Register,
 
 		// API-only modules
 		customevent.Register,