From de4dfcf1012224710f2adba6a90791ac3928b3f6 Mon Sep 17 00:00:00 2001
From: Dmitry Sergeev <mrjitten@protonmail.com>
Date: Thu, 17 Sep 2026 20:39:41 +0300
Subject: [PATCH] tests

---
 internal/video/pattern_test.go | 47 +++++++++++++++++++
 internal/video/runner.go       |  5 ---
 internal/video/runner_test.go  | 82 ++++++++++++++++++++++++++++++++++
 3 files changed, 129 insertions(+), 5 deletions(-)
 create mode 100644 internal/video/pattern_test.go
 create mode 100644 internal/video/runner_test.go

diff --git a/internal/video/pattern_test.go b/internal/video/pattern_test.go
new file mode 100644
index 0000000..9bce8ba
--- /dev/null
+++ b/internal/video/pattern_test.go
@@ -0,0 +1,47 @@
+package video
+
+import "testing"
+
+func TestPatterns(t *testing.T) {
+	got := Patterns()
+	if len(got) == 0 {
+		t.Fatal("Patterns returned no video patterns")
+	}
+
+	seen := make(map[string]struct{}, len(got))
+	for i, pattern := range got {
+		if pattern.Name == "" {
+			t.Fatalf("pattern %d has an empty name", i)
+		}
+		if pattern.Description == "" {
+			t.Fatalf("pattern %q has an empty description", pattern.Name)
+		}
+		if !HasPattern(pattern.Name) {
+			t.Fatalf("Patterns returned %q, but HasPattern rejected it", pattern.Name)
+		}
+		if _, exists := seen[pattern.Name]; exists {
+			t.Fatalf("duplicate pattern name %q", pattern.Name)
+		}
+		seen[pattern.Name] = struct{}{}
+		if i > 0 && got[i-1].Name >= pattern.Name {
+			t.Fatalf("patterns are not sorted: %q appears before %q", got[i-1].Name, pattern.Name)
+		}
+	}
+}
+
+func TestHasPatternRejectsUnknownName(t *testing.T) {
+	if HasPattern("not-a-pattern") {
+		t.Fatal("HasPattern accepted an unknown pattern")
+	}
+}
+
+func TestPatternRegistryKeysMatchNames(t *testing.T) {
+	for name, pattern := range patterns {
+		if pattern.Name != name {
+			t.Errorf("pattern map key %q does not match pattern name %q", name, pattern.Name)
+		}
+		if pattern.kernelPath == "" {
+			t.Errorf("pattern %q has an empty kernel path", name)
+		}
+	}
+}
diff --git a/internal/video/runner.go b/internal/video/runner.go
index c66b637..500d0d7 100644
--- a/internal/video/runner.go
+++ b/internal/video/runner.go
@@ -101,11 +101,6 @@ func buildTextOverlay(cfg Config) (overlay *generator.TextOverlay, resultErr err
 	if cfg.Overlay.Text == "" {
 		return nil, nil
 	}
-	if cfg.Overlay.X < 0 || cfg.Overlay.X > int(cfg.Width()) ||
-		cfg.Overlay.Y < 0 || cfg.Overlay.Y > int(cfg.Height()) {
-		return nil, fmt.Errorf("text overlay position (%d, %d) is outside the %dx%d video frame",
-			cfg.Overlay.X, cfg.Overlay.Y, cfg.Width(), cfg.Height())
-	}
 
 	face, err := generator.LoadFace("assets/fonts/JetBrainsMonoNLNerdFontMono-Regular.ttf", 48)
 	if err != nil {
diff --git a/internal/video/runner_test.go b/internal/video/runner_test.go
new file mode 100644
index 0000000..08dbe21
--- /dev/null
+++ b/internal/video/runner_test.go
@@ -0,0 +1,82 @@
+package video
+
+import (
+	"strings"
+	"testing"
+
+	"mxl-pattern-generator/internal/flowdef"
+)
+
+const testVideoID = "b3bb5be7-9fe9-4324-a5bb-4c70e1084449"
+
+func testConfig(t *testing.T, overlay OverlayConfig) Config {
+	t.Helper()
+	definition, err := flowdef.NewV210Video(
+		testVideoID,
+		1920,
+		1080,
+		flowdef.Rational{Numerator: 50, Denominator: 1},
+	)
+	if err != nil {
+		t.Fatalf("NewV210Video: %v", err)
+	}
+	return Config{Definition: definition, Pattern: "ebu75", Overlay: overlay}
+}
+
+func TestBuildTextOverlayDisabled(t *testing.T) {
+	overlay, err := buildTextOverlay(testConfig(t, OverlayConfig{}))
+	if err != nil {
+		t.Fatalf("buildTextOverlay: %v", err)
+	}
+	if overlay != nil {
+		t.Fatal("buildTextOverlay returned an overlay for empty text")
+	}
+}
+
+func TestBuildTextOverlayPositioning(t *testing.T) {
+	// Production assets are resolved from the repository root.
+	t.Chdir("../..")
+
+	tests := []struct {
+		name    string
+		overlay OverlayConfig
+	}{
+		{name: "explicit", overlay: OverlayConfig{Text: "MXL", X: 120, Y: 48}},
+		{name: "preset", overlay: OverlayConfig{Text: "MXL", Position: "cc"}},
+		{name: "preset ignores explicit coordinates", overlay: OverlayConfig{Text: "MXL", X: -1, Y: -1, Position: "cc"}},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			overlay, err := buildTextOverlay(testConfig(t, tc.overlay))
+			if err != nil {
+				t.Fatalf("buildTextOverlay: %v", err)
+			}
+			if overlay == nil {
+				t.Fatal("buildTextOverlay returned nil")
+			}
+		})
+	}
+}
+
+func TestBuildTextOverlayRejectsInvalidPosition(t *testing.T) {
+	t.Chdir("../..")
+
+	tests := []struct {
+		name       string
+		overlay    OverlayConfig
+		wantErrSub string
+	}{
+		{name: "negative", overlay: OverlayConfig{Text: "MXL", X: -6}, wantErrSub: "must not be negative"},
+		{name: "unaligned x", overlay: OverlayConfig{Text: "MXL", X: 7}, wantErrSub: "divisible by 6"},
+		{name: "right overflow", overlay: OverlayConfig{Text: "MXL", X: 1902}, wantErrSub: "does not fit"},
+		{name: "bottom overflow", overlay: OverlayConfig{Text: "MXL", Y: 1070}, wantErrSub: "does not fit"},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			_, err := buildTextOverlay(testConfig(t, tc.overlay))
+			if err == nil || !strings.Contains(err.Error(), tc.wantErrSub) {
+				t.Fatalf("error = %v, want substring %q", err, tc.wantErrSub)
+			}
+		})
+	}
+}