feat: add --dry-run flag (#15)

* feat: add --dry-run flag

Fixes #14

Signed-off-by: Christian Winther <jippignu@gmail.com>

* docs: update docs a bit

---------

Signed-off-by: Christian Winther <jippignu@gmail.com>

Author: jippi

README.md

@@ -156,17 +156,53 @@ NAME:
    scm-engine evaluate - Evaluate a Merge Request
 
 USAGE:
-   scm-engine evaluate [command options]
+   scm-engine evaluate [command options] [id, id, ...]
 
 OPTIONS:
+   --project value                                                GitLab project (example: 'gitlab-org/gitlab') [$GITLAB_PROJECT, $CI_PROJECT_PATH]
    --id value, --merge-request-id value, --pull-request-id value  The pull/merge to process, if not provided as a CLI flag [$CI_MERGE_REQUEST_IID]
+   --help, -h                                                     show help
 
 GLOBAL OPTIONS:
    --config value     Path to the scm-engine config file (default: ".scm-engine.yml") [$SCM_ENGINE_CONFIG_FILE]
    --api-token value  GitHub/GitLab API token [$SCM_ENGINE_TOKEN]
-   --project value    GitLab project (example: 'gitlab-org/gitlab') [$GITLAB_PROJECT, $CI_PROJECT_PATH]
    --base-url value   Base URL for the SCM instance (default: "https://gitlab.com/") [$GITLAB_BASEURL, $CI_SERVER_URL]
+   --dry-run          Dry run, don't actually _do_ actions, just print them (default: false)
    --help, -h         show help
+   --version, -v      print the version
+```
+
+### `server`
+
+Point your GitLab webhook at the `/gitlab` endpoint.
+
+Support the following events, and they will both trigger an Merge Request `evaluation`
+
+- [`Comments`](https://docs.gitlab.com/ee/user/project/integrations/webhook_events.html#comment-events) - A comment is made or edited on an issue or merge request.
+- [`Merge request events`](https://docs.gitlab.com/ee/user/project/integrations/webhook_events.html#merge-request-events) - A merge request is created, updated, or merged.
+
+> [!TIP]
+> You have access to the raw webhook event payload via `webhook_event.*` fields in Expr script fields when using `server` mode. See the [GitLab Webhook Events documentation](https://docs.gitlab.com/ee/user/project/integrations/webhook_events.html) for available fields.
+
+```plain
+NAME:
+   scm-engine server - Start HTTP server for webhook event driven usage
+
+USAGE:
+   scm-engine server [command options]
+
+OPTIONS:
+   --webhook-secret value  Used to validate received payloads. Sent with the request in the X-Gitlab-Token HTTP header [$SCM_ENGINE_WEBHOOK_SECRET]
+   --listen value          Port the HTTP server should listen on (default: "0.0.0.0:3000") [$SCM_ENGINE_LISTEN]
+   --help, -h              show help
+
+GLOBAL OPTIONS:
+   --config value     Path to the scm-engine config file (default: ".scm-engine.yml") [$SCM_ENGINE_CONFIG_FILE]
+   --api-token value  GitHub/GitLab API token [$SCM_ENGINE_TOKEN]
+   --base-url value   Base URL for the SCM instance (default: "https://gitlab.com/") [$GITLAB_BASEURL, $CI_SERVER_URL]
+   --dry-run          Dry run, don't actually _do_ actions, just print them (default: false)
+   --help, -h         show help
+   --version, -v      print the version
 ```
 
 ## Configuration file

cmd/cmd_evaluate.go

@@ -12,6 +12,7 @@ import (
 
 func Evaluate(cCtx *cli.Context) error {
 	ctx := state.ContextWithProjectID(cCtx.Context, cCtx.String(FlagSCMProject))
+	ctx = state.ContextWithDryRun(ctx, cCtx.Bool(FlagDryRun))
 
 	cfg, err := config.LoadFile(cCtx.String(FlagConfigFile))
 	if err != nil {

cmd/cmd_server.go

@@ -176,7 +176,9 @@ func Server(cCtx *cli.Context) error { //nolint:unparam
 		ReadTimeout:  5 * time.Second,
 		WriteTimeout: 5 * time.Second,
 		BaseContext: func(l net.Listener) context.Context {
-			return cCtx.Context
+			ctx := state.ContextWithDryRun(cCtx.Context, cCtx.Bool(FlagDryRun))
+
+			return ctx
 		},
 	}
 

cmd/conventions.go

@@ -1,11 +1,12 @@
 package cmd
 
 const (
-	FlagConfigFile     = "config"
 	FlagAPIToken       = "api-token"
-	FlagSCMProject     = "project"
-	FlagSCMBaseURL     = "base-url"
+	FlagConfigFile     = "config"
+	FlagDryRun         = "dry-run"
 	FlagMergeRequestID = "id"
+	FlagSCMBaseURL     = "base-url"
+	FlagSCMProject     = "project"
+	FlagServerListen   = "listen"
 	FlagWebhookSecret  = "webhook-secret"
-	FlagServerListen   = "listen-port"
 )

cmd/shared.go

@@ -84,6 +84,12 @@ func ProcessMR(ctx context.Context, client scm.Client, cfg *config.Config, mr st
 }
 
 func updateMergeRequest(ctx context.Context, client scm.Client, update *scm.UpdateMergeRequestOptions) error {
+	if state.IsDryRun(ctx) {
+		slogctx.Info(ctx, "In dry-run, dumping the update struct we would send to GitLab", slog.Any("changes", update))
+
+		return nil
+	}
+
 	_, err := client.MergeRequests().Update(ctx, update)
 
 	return err
@@ -117,6 +123,10 @@ func syncLabels(ctx context.Context, client scm.Client, remote []*scm.Label, req
 
 		slogctx.Info(ctx, "Creating label", slog.String("label", label.Name))
 
+		if state.IsDryRun(ctx) {
+			continue
+		}
+
 		_, resp, err := client.Labels().Create(ctx, &scm.CreateLabelOptions{
 			Name:        &label.Name,        //nolint:gosec
 			Color:       &label.Color,       //nolint:gosec
@@ -148,6 +158,10 @@ func syncLabels(ctx context.Context, client scm.Client, remote []*scm.Label, req
 
 		slogctx.Info(ctx, "Updating label", slog.String("label", label.Name))
 
+		if state.IsDryRun(ctx) {
+			continue
+		}
+
 		_, _, err := client.Labels().Update(ctx, &scm.UpdateLabelOptions{
 			Name:        &label.Name,        //nolint:gosec
 			Color:       &label.Color,       //nolint:gosec

go.mod

@@ -14,7 +14,6 @@ require (
 	github.com/iancoleman/strcase v0.3.0
 	github.com/lmittmann/tint v1.0.4
 	github.com/muesli/termenv v0.15.2
-	github.com/reugn/pkgslog v0.2.0
 	github.com/samber/slog-multi v1.0.2
 	github.com/teacat/noire v1.1.0
 	github.com/urfave/cli/v2 v2.27.2

go.sum

@@ -67,8 +67,6 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/remyoudompheng/bigfft v0.0.0-20200410134404-eec4a21b6bb0 h1:OdAsTTz6OkFY5QxjkYwrChwuRruF69c169dPK26NUlk=
 github.com/remyoudompheng/bigfft v0.0.0-20200410134404-eec4a21b6bb0/go.mod h1:qqbHyh8v60DhA7CoWK5oRCqLrMHRGoxYCSS9EjAz6Eo=
-github.com/reugn/pkgslog v0.2.0 h1:Kedn37OrnOh+5cBxNNwrUHR7e8175CQLk8QztbPZ+VQ=
-github.com/reugn/pkgslog v0.2.0/go.mod h1:Gb0SqIq+BCzAeTeWdHxiVz4S206U30WBd6gSsnjfMxo=
 github.com/rivo/uniseg v0.1.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.2.0/go.mod h1:J6wj4VEh+S6ZtnVlnTBMWIodfgj8LQOQFoIToxlJtxc=
 github.com/rivo/uniseg v0.4.7 h1:WUdvkW8uEhrYfLC4ZzdpI2ztxP1I582+49Oc5Mq64VQ=

main.go

@@ -60,7 +60,6 @@ func main() {
 					"SCM_ENGINE_TOKEN",
 				},
 			},
-
 			&cli.StringFlag{
 				Name:  cmd.FlagSCMBaseURL,
 				Usage: "Base URL for the SCM instance",
@@ -70,12 +69,18 @@ func main() {
 					"CI_SERVER_URL",
 				},
 			},
+			&cli.BoolFlag{
+				Name:  cmd.FlagDryRun,
+				Usage: "Dry run, don't actually _do_ actions, just print them",
+			},
 		},
 		Commands: []*cli.Command{
 			{
-				Name:   "evaluate",
-				Usage:  "Evaluate a Merge Request",
-				Action: cmd.Evaluate,
+				Name:      "evaluate",
+				Usage:     "Evaluate a Merge Request",
+				Args:      true,
+				ArgsUsage: " [id, id, ...]",
+				Action:    cmd.Evaluate,
 				Flags: []cli.Flag{
 					&cli.StringFlag{
 						Name:     cmd.FlagSCMProject,

pkg/scm/gitlab/client_actioner.go

@@ -4,9 +4,11 @@ import (
 	"context"
 	"errors"
 	"fmt"
+	"log/slog"
 
 	"github.com/jippi/scm-engine/pkg/scm"
 	"github.com/jippi/scm-engine/pkg/state"
+	slogctx "github.com/veqryn/slog-context"
 	"github.com/xanzy/go-gitlab"
 )
 
@@ -35,11 +37,23 @@ func (c *Client) ApplyStep(ctx context.Context, update *scm.UpdateMergeRequestOp
 		update.DiscussionLocked = gitlab.Ptr(false)
 
 	case "approve":
+		if state.IsDryRun(ctx) {
+			slogctx.Info(ctx, "Approving MR")
+
+			return nil
+		}
+
 		_, _, err := c.wrapped.MergeRequestApprovals.ApproveMergeRequest(state.ProjectIDFromContext(ctx), state.MergeRequestIDFromContextInt(ctx), &gitlab.ApproveMergeRequestOptions{})
 
 		return err
 
 	case "unapprove":
+		if state.IsDryRun(ctx) {
+			slogctx.Info(ctx, "Unapproving MR")
+
+			return nil
+		}
+
 		_, err := c.wrapped.MergeRequestApprovals.UnapproveMergeRequest(state.ProjectIDFromContext(ctx), state.MergeRequestIDFromContextInt(ctx))
 
 		return err
@@ -59,6 +73,12 @@ func (c *Client) ApplyStep(ctx context.Context, update *scm.UpdateMergeRequestOp
 			return errors.New("step field 'message' must not be an empty string")
 		}
 
+		if state.IsDryRun(ctx) {
+			slogctx.Info(ctx, "Commenting on MR", slog.String("message", msgString))
+
+			return nil
+		}
+
 		_, _, err := c.wrapped.Notes.CreateMergeRequestNote(state.ProjectIDFromContext(ctx), state.MergeRequestIDFromContextInt(ctx), &gitlab.CreateMergeRequestNoteOptions{
 			Body: gitlab.Ptr(msgString),
 		})

pkg/state/context.go

@@ -2,6 +2,7 @@ package state
 
 import (
 	"context"
+	"log/slog"
 	"strconv"
 
 	slogctx "github.com/veqryn/slog-context"
@@ -11,6 +12,7 @@ type contextKey uint
 
 const (
 	projectID contextKey = iota
+	dryRun
 	mergeRequestID
 )
 
@@ -27,12 +29,23 @@ func ProjectIDFromContext(ctx context.Context) string {
 }
 
 func ContextWithProjectID(ctx context.Context, value string) context.Context {
-	ctx = slogctx.With(ctx, "project_id", value)
+	ctx = slogctx.With(ctx, slog.String("project_id", value))
 	ctx = context.WithValue(ctx, projectID, value)
 
 	return ctx
 }
 
+func ContextWithDryRun(ctx context.Context, dry bool) context.Context {
+	ctx = slogctx.With(ctx, slog.Bool("dry_run", dry))
+	ctx = context.WithValue(ctx, dryRun, dry)
+
+	return ctx
+}
+
+func IsDryRun(ctx context.Context) bool {
+	return ctx.Value(dryRun).(bool) //nolint:forcetypeassert
+}
+
 func ContextWithMergeRequestID(ctx context.Context, id string) context.Context {
 	ctx = slogctx.With(ctx, "merge_request_id", id)
 	ctx = context.WithValue(ctx, mergeRequestID, id)

pkg/tui/context.go

@@ -7,7 +7,6 @@ import (
 
 	"github.com/charmbracelet/lipgloss"
 	"github.com/muesli/termenv"
-	"github.com/reugn/pkgslog"
 	slogmulti "github.com/samber/slog-multi"
 	slogctx "github.com/veqryn/slog-context"
 	slogdedup "github.com/veqryn/slog-dedup"
@@ -33,11 +32,6 @@ func NewContext(ctx context.Context, stdout, stderr io.Writer) context.Context {
 		ctx,
 		slog.New(
 			slogmulti.
-				Pipe(
-					func(next slog.Handler) slog.Handler {
-						return pkgslog.NewPackageHandler(next, packageLogLevels())
-					},
-				).
 				Pipe(
 					slogctx.NewMiddleware(&slogctx.HandlerOptions{}),
 				).

pkg/tui/logger.go

@@ -32,27 +32,6 @@ func ParseLogLevel(name string, fallback slog.Level) slog.Level {
 	}
 }
 
-func pkgLogLevel(name string, fallback slog.Level) slog.Level {
-	return ParseLogLevel(os.Getenv(name+"_LOG_LEVEL"), fallback)
-}
-
-func packageLogLevels() map[string]slog.Level {
-	logLevel := ParseLogLevel(os.Getenv("LOG_LEVEL"), slog.LevelInfo)
-
-	lowestOf := func(in slog.Level) slog.Level {
-		if in < logLevel {
-			return in
-		}
-
-		return logLevel
-	}
-
-	return map[string]slog.Level{
-		pkgPrefix + "/pkg/parser":  pkgLogLevel("PARSER", lowestOf(slog.LevelWarn)),
-		pkgPrefix + "/pkg/scanner": pkgLogLevel("SCANNER", lowestOf(slog.LevelWarn)),
-	}
-}
-
 func logHandler(out io.Writer) slog.Handler {
 	logLevel := ParseLogLevel(os.Getenv("LOG_LEVEL"), slog.LevelInfo)
 
@@ -69,7 +48,8 @@ func logHandler(out io.Writer) slog.Handler {
 	return devslog.NewHandler(
 		out,
 		&devslog.Options{
-			SortKeys: true,
+			SortKeys:          true,
+			MaxSlicePrintSize: 999,
 			HandlerOptions: &slog.HandlerOptions{
 				Level:     logLevel,
 				AddSource: logLevel == slog.LevelDebug,