Unify active task loading across API handlers

internal/server/changes.go

@@ -2,7 +2,6 @@ package server
 
 import (
 	"errors"
-	"fmt"
 	"net/http"
 	"regexp"
 
@@ -13,19 +12,8 @@ import (
 var objectID = regexp.MustCompile(`^[0-9a-f]{40}([0-9a-f]{24})?$`)
 
 func (s *Server) GetTaskChanges(w http.ResponseWriter, r *http.Request, taskID string, params api.GetTaskChangesParams) {
-	t, err := s.store.GetTask(r.Context(), taskID)
-	if err != nil {
-		writeStoreError(w, err)
-		return
-	}
-	if t.Status != api.TaskStatusActive {
-		writeError(w, http.StatusConflict, fmt.Errorf("task %s is %s and has no worktree", t.Id, t.Status))
-		return
-	}
-
-	p, err := s.store.GetProject(r.Context(), t.ProjectId)
-	if err != nil {
-		writeStoreError(w, err)
+	t, p, ok := s.activeTaskProject(w, r, taskID)
+	if !ok {
 		return
 	}
 
@@ -96,13 +84,8 @@ func (s *Server) stepBase(r *http.Request, t api.Task, snap api.Snapshot) (strin
 }
 
 func (s *Server) GetTaskDiff(w http.ResponseWriter, r *http.Request, taskID string, params api.GetTaskDiffParams) {
-	t, err := s.store.GetTask(r.Context(), taskID)
-	if err != nil {
-		writeStoreError(w, err)
-		return
-	}
-	if t.Status != api.TaskStatusActive {
-		writeError(w, http.StatusConflict, fmt.Errorf("task %s is %s and has no worktree", t.Id, t.Status))
+	t, ok := s.activeTask(w, r, taskID)
+	if !ok {
 		return
 	}
 	if !objectID.MatchString(params.Base) || !objectID.MatchString(params.Tree) {