test(tui): add tier 1 unit tests for pure logic functions

Cover search filtering, intent matching, card affordances, checklist
parsing, template slot discovery/resolve, date grouping, and truncation.

internal/tui/list_test.go

@@ -0,0 +1,94 @@
+package tui
+
+import (
+	"testing"
+	"time"
+
+	"github.com/lerko/nib/internal/db"
+)
+
+func TestGroupByDate(t *testing.T) {
+	may19 := time.Date(2026, 5, 19, 10, 0, 0, 0, time.UTC)
+	may19b := time.Date(2026, 5, 19, 14, 0, 0, 0, time.UTC)
+	may18 := time.Date(2026, 5, 18, 9, 0, 0, 0, time.UTC)
+
+	entities := []*db.Entity{
+		{ID: "1", CreatedAt: may19, Body: "a"},
+		{ID: "2", CreatedAt: may19b, Body: "b"},
+		{ID: "3", CreatedAt: may18, Body: "c"},
+	}
+
+	groups := groupByDate(entities)
+	if len(groups) != 2 {
+		t.Fatalf("expected 2 groups, got %d", len(groups))
+	}
+	if len(groups[0].entities) != 2 {
+		t.Fatalf("first group should have 2 entities, got %d", len(groups[0].entities))
+	}
+	if len(groups[1].entities) != 1 {
+		t.Fatalf("second group should have 1 entity, got %d", len(groups[1].entities))
+	}
+	if groups[0].label != "may 19" {
+		t.Fatalf("first group label = %q, want %q", groups[0].label, "may 19")
+	}
+}
+
+func TestGroupByDate_Empty(t *testing.T) {
+	groups := groupByDate(nil)
+	if len(groups) != 0 {
+		t.Fatalf("expected 0 groups, got %d", len(groups))
+	}
+}
+
+func TestGroupByDate_SingleEntity(t *testing.T) {
+	e := []*db.Entity{{ID: "1", CreatedAt: time.Now(), Body: "solo"}}
+	groups := groupByDate(e)
+	if len(groups) != 1 || len(groups[0].entities) != 1 {
+		t.Fatal("single entity should produce 1 group with 1 entity")
+	}
+}
+
+func TestTruncate(t *testing.T) {
+	tests := []struct {
+		name   string
+		input  string
+		maxLen int
+		want   string
+	}{
+		{"short enough", "hello", 10, "hello"},
+		{"exact length", "hello", 5, "hello"},
+		{"truncated", "hello world", 6, "hello…"},
+		{"very short max", "hello", 3, "…"},
+		{"unicode", "héllo wörld", 7, "héllo …"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := truncate(tt.input, tt.maxLen)
+			if got != tt.want {
+				t.Fatalf("truncate(%q, %d) = %q, want %q", tt.input, tt.maxLen, got, tt.want)
+			}
+		})
+	}
+}
+
+func TestStripAnsi(t *testing.T) {
+	tests := []struct {
+		name  string
+		input string
+		want  string
+	}{
+		{"no ansi", "hello", "hello"},
+		{"with color", "\x1b[31mred\x1b[0m", "red"},
+		{"empty", "", ""},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			got := stripAnsi(tt.input)
+			if got != tt.want {
+				t.Fatalf("stripAnsi(%q) = %q, want %q", tt.input, got, tt.want)
+			}
+		})
+	}
+}