feat: align image rendering with Confluence default

renderer/image_test.go

@@ -0,0 +1,84 @@
+package renderer
+
+import "testing"
+
+func TestCalculateAlign(t *testing.T) {
+	tests := []struct {
+		name             string
+		configuredAlign  string
+		width            string
+		expectedAlign    string
+	}{
+		{"No alignment configured", "", "1000", ""},
+		{"No width available", "center", "", "center"},
+		{"Below threshold", "center", "500", "center"},
+		{"At threshold", "center", "760", "wide"},
+		{"Above threshold", "center", "1000", "wide"},
+		{"Left below threshold", "left", "700", "left"},
+		{"Left at threshold", "left", "760", "wide"},
+		{"Invalid width", "center", "abc", "center"},
+		{"Large image", "center", "2000", "wide"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := calculateAlign(tt.configuredAlign, tt.width)
+			if result != tt.expectedAlign {
+				t.Errorf("calculateAlign(%q, %q) = %q, want %q", tt.configuredAlign, tt.width, result, tt.expectedAlign)
+			}
+		})
+	}
+}
+
+func TestCalculateLayout(t *testing.T) {
+	tests := []struct {
+		name           string
+		align          string
+		width          string
+		expectedLayout string
+	}{
+		{"Left alignment", "left", "500", "align-start"},
+		{"Center alignment", "center", "500", "center"},
+		{"Right alignment", "right", "500", "align-end"},
+		{"Wide alignment", "wide", "1000", "center"},
+		{"Full-width threshold", "center", "1800", "full-width"},
+		{"Above full-width", "left", "2000", "full-width"},
+		{"Below full-width", "center", "1799", "center"},
+		{"No alignment", "", "1000", ""},
+		{"Unknown alignment", "justify", "500", ""},
+		{"Invalid width", "center", "abc", "center"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := calculateLayout(tt.align, tt.width)
+			if result != tt.expectedLayout {
+				t.Errorf("calculateLayout(%q, %q) = %q, want %q", tt.align, tt.width, result, tt.expectedLayout)
+			}
+		})
+	}
+}
+
+func TestCalculateDisplayWidth(t *testing.T) {
+	tests := []struct {
+		name          string
+		originalWidth string
+		layout        string
+		expectedWidth string
+	}{
+		{"Full-width layout", "2000", "full-width", "1800"},
+		{"Center layout keeps original", "1000", "center", "1000"},
+		{"Align-start keeps original", "800", "align-start", "800"},
+		{"Empty original", "", "center", ""},
+		{"Empty layout", "1000", "", "1000"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			result := calculateDisplayWidth(tt.originalWidth, tt.layout)
+			if result != tt.expectedWidth {
+				t.Errorf("calculateDisplayWidth(%q, %q) = %q, want %q", tt.originalWidth, tt.layout, result, tt.expectedWidth)
+			}
+		})
+	}
+}