feat(search): find a task by its label

Search covered task text only, so "regnskab" found nothing with the task
labelled @regnskab sitting in front of you — which reads as the search
box having lost it.

A label is often the only thing you remember. "That thing about the
accounts" is a search for @regnskab, not for any word in the title.

The label side is a plain lowercase match rather than a second FTS index.
Labels are short, and their names are typed by the same person now
searching for them, so there is no spelling to be generous about — the
diacritic folding that earns its keep on task text does not earn a second
index here.

The join sits inside the WHERE the visibility rules already build, so
somebody else's label cannot pull their task into your results. There is
a test for that, because it is the kind of thing an OR is good at
breaking.

Co-Authored-By: Claude Opus 5 <[email protected]>

internal/httpapi/views_test.go

@@ -0,0 +1,55 @@
+package httpapi
+
+import "testing"
+
+// A label is how you find a task whose wording you have forgotten. Search
+// covered the text only, so "regnskab" found nothing even with the task
+// labelled @regnskab in front of you.
+func TestSearchFindsTasksByLabel(t *testing.T) {
+	ts := newTestServer(t)
+	ts.bootstrap(t)
+
+	ts.do(t, "POST", "/api/v1/tasks/quick-add",
+		map[string]any{"text": "ring til revisoren @regnskab"})
+	ts.do(t, "POST", "/api/v1/tasks/quick-add",
+		map[string]any{"text": "køb kaffe"})
+
+	_, body := ts.do(t, "GET", "/api/v1/search?q=regnskab", nil)
+	tasks, _ := body["tasks"].([]any)
+	if len(tasks) != 1 {
+		t.Fatalf("found %d tasks searching for a label, want 1: %v", len(tasks), body)
+	}
+	if got := tasks[0].(map[string]any)["content"]; got != "ring til revisoren" {
+		t.Errorf("found %v", got)
+	}
+}
+
+// The text search still works, and a label match does not swallow it.
+func TestSearchStillFindsTasksByText(t *testing.T) {
+	ts := newTestServer(t)
+	ts.bootstrap(t)
+
+	ts.do(t, "POST", "/api/v1/tasks/quick-add", map[string]any{"text": "køb grøn maling"})
+
+	// Diacritic folding still applies to the text side.
+	_, body := ts.do(t, "GET", "/api/v1/search?q=gron", nil)
+	if tasks, _ := body["tasks"].([]any); len(tasks) != 1 {
+		t.Errorf("searching \"gron\" found %d tasks, want 1", len(tasks))
+	}
+}
+
+// Somebody else's label must not pull their task into your results — the label
+// join has to stay inside the visibility the outer query already applies.
+func TestSearchByLabelStaysWithinWhatYouCanSee(t *testing.T) {
+	ts := newTestServer(t)
+	ts.bootstrap(t)
+
+	other := ts.newUser(t, "[email protected]", "Anden")
+	other.do(t, "POST", "/api/v1/tasks/quick-add",
+		map[string]any{"text": "deres hemmelighed @regnskab"})
+
+	_, body := ts.do(t, "GET", "/api/v1/search?q=regnskab", nil)
+	if tasks, _ := body["tasks"].([]any); len(tasks) != 0 {
+		t.Errorf("found somebody else's task: %v", tasks)
+	}
+}

internal/store/tasks.go

@@ -136,8 +136,23 @@ func (db *DB) ListTasks(ctx context.Context, userID string, f TaskFilter) ([]Tas
 		args = append(args, f.DueFrom)
 	}
 	if expr := MatchExpr(f.Search); expr != "" {
-		where = append(where, `t.rowid IN (SELECT rowid FROM tasks_fts WHERE tasks_fts MATCH ?)`)
-		args = append(args, expr)
+		// Text or a label. A label is how you find a task whose wording you have
+		// forgotten — "that thing about the accounts" is a search for @regnskab —
+		// and leaving them out made the box look like it had lost the task.
+		//
+		// The label side is a plain lowercase match rather than another FTS index:
+		// labels are short, and their names are typed by the person searching for
+		// them, so there is no spelling to be generous about. The diacritic
+		// folding that matters for task text does not earn a second index here.
+		where = append(where, `(
+			t.rowid IN (SELECT rowid FROM tasks_fts WHERE tasks_fts MATCH ?)
+			OR t.id IN (
+				SELECT tl.task_id FROM task_labels tl
+				JOIN labels l ON l.id = tl.label_id
+				WHERE lower(l.name) LIKE ?
+			)
+		)`)
+		args = append(args, expr, "%"+strings.ToLower(strings.TrimSpace(f.Search))+"%")
 	}
 	if f.FilterSQL != "" {
 		where = append(where, "("+f.FilterSQL+")")