Add test for draw.GraphAttribute

CHANGELOG.md

@@ -5,7 +5,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),  and this project
 adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## [0.17.0] - 2023-04-10
+## [0.17.0] - 2023-04-12
 
 ### Added
 * Added the `draw.GraphAttributes` functional option for `draw.DOT` for rendering graph attributes.

draw/draw.go

@@ -66,8 +66,8 @@ type statement struct {
 //
 //	go run main.go | dot -Tsvg > output.svg
 //
-// DOT also accepts the [draw.GraphAttribute] functional option, which can be
-// used to add global attributes when rendering the graph:
+// DOT also accepts the [GraphAttribute] functional option, which can be used to
+// add global attributes when rendering the graph:
 //
 //	_ = draw.DOT(g, file, draw.GraphAttribute("label", "my-graph"))
 func DOT[K comparable, T any](g graph.Graph[K, T], w io.Writer, options ...func(*description)) error {
@@ -79,7 +79,7 @@ func DOT[K comparable, T any](g graph.Graph[K, T], w io.Writer, options ...func(
 	return renderDOT(w, desc)
 }
 
-// GraphAttribute is a functional option for the [draw.DOT] method.
+// GraphAttribute is a functional option for the [DOT] method.
 func GraphAttribute(key, value string) func(*description) {
 	return func(d *description) {
 		d.Attributes[key] = value

draw/draw_test.go

@@ -364,6 +364,39 @@ func TestRenderDOT(t *testing.T) {
 	}
 }
 
+func TestGraphAttribute(t *testing.T) {
+	tests := map[string]struct {
+		attribute [2]string
+		expected  *description
+	}{
+		"label attribute": {
+			attribute: [2]string{"label", "my-graph"},
+			expected: &description{
+				Attributes: map[string]string{
+					"label": "my-graph",
+				},
+			},
+		},
+	}
+
+	for name, test := range tests {
+		d := &description{
+			Attributes: make(map[string]string),
+		}
+
+		GraphAttribute(test.attribute[0], test.attribute[1])(d)
+
+		stringsAreEqual := func(a, b string) bool {
+			return a == b
+		}
+
+		if !mapsAreEqual(test.expected.Attributes, d.Attributes, stringsAreEqual) {
+			t.Errorf("%s: graph attribute expectation doesn't match: expected %v, got %v", name, test.expected.Attributes, d.Attributes)
+		}
+	}
+
+}
+
 func slicesAreEqual[T any](a, b []T, equals func(a, b T) bool) bool {
 	if len(a) != len(b) {
 		return false