feat: add graph printer

.gitignore

@@ -9,6 +9,6 @@ docs/cmd
 pkg/dib/tests
 pkg/trivy/reports
 venv
-coverage.output
+coverage.*
 .golangci.yml
 golangci-lint-report.xml

Makefile

@@ -42,9 +42,13 @@ RESET := $(shell tput sgr0)
 
 .PHONY: test
 test: ## Run tests
-	@go test -v -race -failfast -coverprofile coverage.output -run $(RUN) $(PKG) | \
+	@go test -v -race -failfast -coverprofile coverage.out -covermode atomic -run $(RUN) $(PKG) | \
         sed 's/RUN/$(BLUE)RUN$(RESET)/g' | \
         sed 's/CONT/$(BLUE)CONT$(RESET)/g' | \
         sed 's/PAUSE/$(BLUE)PAUSE$(RESET)/g' | \
         sed 's/PASS/$(GREEN)PASS$(RESET)/g' | \
         sed 's/FAIL/$(RED)FAIL$(RESET)/g'
+	@go tool cover -html=coverage.out -o coverage.html
+	@echo "To open the html coverage file, use one of the following commands:"
+	@echo "open coverage.html on mac"
+	@echo "xdg-open coverage.html on linux"

pkg/dag/dag.go

@@ -1,6 +1,9 @@
 package dag
 
 import (
+	"cmp"
+	"slices"
+	"strings"
 	"sync"
 
 	"golang.org/x/sync/errgroup"
@@ -204,3 +207,24 @@ func createUniqueVisitorErr(visitor NodeVisitorFuncErr) NodeVisitorFuncErr {
 
 	return uniqueVisitor
 }
+
+func sort(a, b *Node) int {
+	return cmp.Compare(
+		strings.ToLower(a.Image.ShortName),
+		strings.ToLower(b.Image.ShortName),
+	)
+}
+
+func (d *DAG) Sprint(name string) string {
+	d.WalkInDepth(func(node *Node) {
+		slices.SortFunc(node.Children(), sort)
+	})
+
+	slices.SortFunc(d.nodes, sort)
+	rootNode := &Node{
+		Image:    &Image{Name: name},
+		children: d.nodes,
+	}
+
+	return defaultPrinter.WithRoot(rootNode).Srender()
+}

pkg/dag/dag_test.go

@@ -271,3 +271,73 @@ func Test_ListImage(t *testing.T) {
 		"    hash: arm-ag-ed-don\n"
 	assert.Equal(t, expected, DAG.ListImage())
 }
+
+func TestDAG_Sprint(t *testing.T) {
+	t.Parallel()
+
+	t.Run("empty graph", func(t *testing.T) {
+		t.Parallel()
+
+		graph := &dag.DAG{}
+		node := dag.NewNode(nil)
+		graph.AddNode(node)
+
+		assert.Equal(t, "graph\n", graph.Sprint("graph"))
+	})
+
+	t.Run("one node", func(t *testing.T) {
+		t.Parallel()
+
+		graph := &dag.DAG{}
+		node := dag.NewNode(&dag.Image{
+			ShortName: "n1",
+			Hash:      "h1",
+		})
+		graph.AddNode(node)
+
+		expected := `graph
+└───n1 [h1]
+`
+		assert.Equal(t, expected, graph.Sprint("graph"))
+	})
+
+	t.Run("5 nodes", func(t *testing.T) {
+		t.Parallel()
+
+		graph := &dag.DAG{}
+		node1 := dag.NewNode(&dag.Image{
+			ShortName: "n1",
+			Hash:      "h1",
+		})
+		node2 := dag.NewNode(&dag.Image{
+			ShortName: "n2",
+			Hash:      "h2",
+		})
+		node3 := dag.NewNode(&dag.Image{
+			ShortName: "n3",
+			Hash:      "h3",
+		})
+		node4 := dag.NewNode(&dag.Image{
+			ShortName: "n4",
+			Hash:      "h4",
+		})
+		node5 := dag.NewNode(&dag.Image{
+			ShortName: "n5",
+			Hash:      "h5",
+		})
+		node1.AddChild(node2)
+		node1.AddChild(node3)
+		node1.AddChild(node4)
+		node2.AddChild(node5)
+		graph.AddNode(node1)
+
+		expected := `graph
+└──┬n1 [h1]
+   ├──┬n2 [h2]
+   │  └───n5 [h5]
+   ├───n3 [h3]
+   └───n4 [h4]
+`
+		assert.Equal(t, expected, graph.Sprint("graph"))
+	})
+}

pkg/dag/printer.go

@@ -0,0 +1,95 @@
+package dag
+
+import (
+	"fmt"
+	"io"
+	"strings"
+
+	"github.com/pterm/pterm"
+)
+
+var defaultPrinter = GraphPrinter{
+	TopRightCornerString: "└",
+	TopRightDownString:   "├",
+	HorizontalString:     "─",
+	VerticalString:       "│",
+	RightDownLeftString:  "┬",
+	Indent:               3,
+}
+
+type GraphPrinter struct {
+	Root                 *Node
+	TreeStyle            *pterm.Style
+	TextStyle            *pterm.Style
+	TopRightCornerString string
+	TopRightDownString   string
+	HorizontalString     string
+	VerticalString       string
+	RightDownLeftString  string
+	Indent               int
+	Writer               io.Writer
+}
+
+// WithRoot returns a new GraphPrinter with a specific Root node.
+func (p GraphPrinter) WithRoot(root *Node) *GraphPrinter {
+	p.Root = root
+	return &p
+}
+
+// Srender renders the graph as a string.
+func (p GraphPrinter) Srender() string {
+	if p.TreeStyle == nil {
+		p.TreeStyle = pterm.NewStyle()
+	}
+	if p.TextStyle == nil {
+		p.TextStyle = pterm.NewStyle()
+	}
+
+	var result string
+	if p.Root.Image.Name != "" {
+		result += p.TextStyle.Sprint(p.Root.Image.Name) + "\n"
+	}
+	result += walkOverTree(p.Root.Children(), p, "")
+
+	return result
+}
+
+func walkOverTree(nodes []*Node, printer GraphPrinter, prefix string) string {
+	var result string
+	for nodeIndex, node := range nodes {
+		if node.Image == nil {
+			continue
+		}
+
+		txt := fmt.Sprintf("%s [%s]\n", node.Image.ShortName, node.Image.Hash)
+		if len(nodes) > nodeIndex+1 { // if not last in nodes
+			if len(node.Children()) == 0 { // if there are no children
+				result += prefix + printer.TreeStyle.Sprint(printer.TopRightDownString) +
+					strings.Repeat(printer.TreeStyle.Sprint(printer.HorizontalString), printer.Indent) +
+					printer.TextStyle.Sprint(txt)
+			} else { // if there are children
+				result += prefix + printer.TreeStyle.Sprint(printer.TopRightDownString) +
+					strings.Repeat(printer.TreeStyle.Sprint(printer.HorizontalString), printer.Indent-1) +
+					printer.TreeStyle.Sprint(printer.RightDownLeftString) +
+					printer.TextStyle.Sprint(txt)
+				result += walkOverTree(node.Children(), printer,
+					prefix+printer.TreeStyle.Sprint(printer.VerticalString)+strings.Repeat(" ", printer.Indent-1))
+			}
+		} else if len(nodes) == nodeIndex+1 { // if last in nodes
+			if len(node.Children()) == 0 { // if there are no children
+				result += prefix + printer.TreeStyle.Sprint(printer.TopRightCornerString) +
+					strings.Repeat(printer.TreeStyle.Sprint(printer.HorizontalString), printer.Indent) +
+					printer.TextStyle.Sprint(txt)
+			} else { // if there are children
+				result += prefix + printer.TreeStyle.Sprint(printer.TopRightCornerString) +
+					strings.Repeat(printer.TreeStyle.Sprint(printer.HorizontalString), printer.Indent-1) +
+					printer.TreeStyle.Sprint(printer.RightDownLeftString) +
+					printer.TextStyle.Sprint(txt)
+				result += walkOverTree(node.Children(), printer,
+					prefix+strings.Repeat(" ", printer.Indent))
+			}
+		}
+	}
+
+	return result
+}