chore: re-enable nilnil lint for models/actions/task.go (#12768)

I added sentinel error values for jobs not being found and no jobs being updated by the `CreateTaskForRunner` function. This avoids the nilnil antipattern and allows the nilnil lint to be enabled for the `models/actions/task.go` file again.

The handling of these new errors was added to the `PickTask` function in `services/actions/task.go`.

Related issue: https://codeberg.org/forgejo/forgejo/issues/11261

Reviewed-on: https://codeberg.org/forgejo/forgejo/pulls/12768
Reviewed-by: limiting-factor <limiting-factor@noreply.codeberg.org>
Reviewed-by: elle <0xllx0@noreply.codeberg.org>

models/actions/task.go

@@ -6,6 +6,7 @@ package actions
 import (
 	"context"
 	"crypto/subtle"
+	"errors"
 	"fmt"
 	"time"
 
@@ -341,10 +342,15 @@ func GetAvailableJobsForRunner(e db.Engine, runner *ActionRunner) ([]*ActionRunJ
 	return jobs, nil
 }
 
-func CreateTaskForRunner(ctx context.Context, runner *ActionRunner, requestKey, handle *string) (*ActionTask, bool, error) {
+var (
+	ErrNoMatchingJobFound = errors.New("no matching job found")
+	ErrNoJobUpdated       = errors.New("no job updated")
+)
+
+func CreateTaskForRunner(ctx context.Context, runner *ActionRunner, requestKey, handle *string) (*ActionTask, error) {
 	ctx, committer, err := db.TxContext(ctx)
 	if err != nil {
-		return nil, false, err
+		return nil, err
 	}
 	defer committer.Close()
 
@@ -352,7 +358,7 @@ func CreateTaskForRunner(ctx context.Context, runner *ActionRunner, requestKey,
 
 	jobs, err := GetAvailableJobsForRunner(e, runner)
 	if err != nil {
-		return nil, false, err
+		return nil, err
 	}
 
 	// TODO: a more efficient way to filter labels
@@ -365,10 +371,10 @@ func CreateTaskForRunner(ctx context.Context, runner *ActionRunner, requestKey,
 		}
 	}
 	if job == nil {
-		return nil, false, nil
+		return nil, ErrNoMatchingJobFound
 	}
 	if err := job.LoadAttributes(ctx); err != nil {
-		return nil, false, err
+		return nil, err
 	}
 
 	now := timeutil.TimeStampNow()
@@ -393,20 +399,20 @@ func CreateTaskForRunner(ctx context.Context, runner *ActionRunner, requestKey,
 
 	var workflowJob *jobparser.Job
 	if gots, err := jobparser.Parse(job.WorkflowPayload, false); err != nil {
-		return nil, false, fmt.Errorf("parse workflow of job %d: %w", job.ID, err)
+		return nil, fmt.Errorf("parse workflow of job %d: %w", job.ID, err)
 	} else if len(gots) != 1 {
-		return nil, false, fmt.Errorf("workflow of job %d: not single workflow", job.ID)
+		return nil, fmt.Errorf("workflow of job %d: not single workflow", job.ID)
 	} else { //nolint:revive
 		_, workflowJob = gots[0].Job()
 	}
 
 	if _, err := e.Insert(task); err != nil {
-		return nil, false, err
+		return nil, err
 	}
 
 	task.LogFilename = logFileName(job.Run.Repo.FullName(), task.ID)
 	if err := UpdateTask(ctx, task, "log_filename"); err != nil {
-		return nil, false, err
+		return nil, err
 	}
 
 	if len(workflowJob.Steps) > 0 {
@@ -422,7 +428,7 @@ func CreateTaskForRunner(ctx context.Context, runner *ActionRunner, requestKey,
 			}
 		}
 		if _, err := e.Insert(steps); err != nil {
-			return nil, false, err
+			return nil, err
 		}
 		task.Steps = steps
 	}
@@ -430,18 +436,18 @@ func CreateTaskForRunner(ctx context.Context, runner *ActionRunner, requestKey,
 	job.TaskID = task.ID
 	// We never have to send a notification here because the job is started with a not done status.
 	if n, err := UpdateRunJobWithoutNotification(ctx, job, builder.Eq{"task_id": 0}); err != nil {
-		return nil, false, err
+		return nil, err
 	} else if n != 1 {
-		return nil, false, nil
+		return nil, ErrNoJobUpdated
 	}
 
 	task.Job = job
 
 	if err := committer.Commit(); err != nil {
-		return nil, false, err
+		return nil, err
 	}
 
-	return task, true, nil
+	return task, nil
 }
 
 // Placeholder tasks are created when the status/content of an [ActionRunJob] is resolved by Forgejo without dispatch to