visualiser: Allow spacing in node names

internal/graph/graph.go

@@ -1,5 +1,7 @@
 package graph
 
+import "slices"
+
 func New() *Graph {
 	return &Graph{
 		graph:      make(map[int][]int),
@@ -75,6 +77,21 @@ type Info struct {
 	Transitions   []Transition
 }
 
+func (g *Graph) Nodes() []int {
+	var nodes []int
+	for node, ok := range g.validNodes {
+		if !ok {
+			continue
+		}
+
+		nodes = append(nodes, node)
+	}
+
+	slices.Sort(nodes)
+
+	return nodes
+}
+
 func (g *Graph) Info() Info {
 	var i Info
 	for _, node := range g.nodeOrder {

internal/graph/graph_test.go

@@ -53,4 +53,8 @@ func TestGraph(t *testing.T) {
 		},
 	}
 	require.Equal(t, expected, actual)
+
+	actualNodes := g.Nodes()
+	expectedNodes := []int{1, 2, 3, 4, 5}
+	require.Equal(t, expectedNodes, actualNodes)
 }

internal/util/util.go

@@ -0,0 +1,15 @@
+package util
+
+import "unicode"
+
+func CamelCaseToSpacing(s string) string {
+	var result []rune
+	for i, r := range s {
+		if unicode.IsUpper(r) && i > 0 {
+			result = append(result, ' ')
+		}
+
+		result = append(result, r)
+	}
+	return string(result)
+}

internal/util/util_test.go

@@ -0,0 +1,31 @@
+package util_test
+
+import (
+	"fmt"
+	"testing"
+
+	"github.com/stretchr/testify/require"
+
+	"github.com/luno/workflow/internal/util"
+)
+
+func TestCamelCaseToSpacing(t *testing.T) {
+	tests := []struct {
+		input    string
+		expected string
+	}{
+		{"camelCase", "camel Case"},
+		{"thisIsATest", "this Is A Test"},
+		{"helloWorld", "hello World"},
+		{"singleWord", "single Word"},
+		{"Lowercase", "Lowercase"}, // No change if no camel case
+		{"", ""},                   // Empty string case
+	}
+
+	for i, test := range tests {
+		t.Run(fmt.Sprintf("case %v: %v", i+1, test.input), func(t *testing.T) {
+			result := util.CamelCaseToSpacing(test.input)
+			require.Equal(t, test.expected, result)
+		})
+	}
+}

testdata/graph-visualisation.md

@@ -5,7 +5,12 @@ title: Diagram of example Workflow
 stateDiagram-v2
 	direction LR
 
-	start-->middle
-	start-->end
-	middle-->end
+	9: Start
+	10: Middle
+	11: End
+
+
+	9-->10
+	9-->11
+	10-->11
 ```

visualiser.go

@@ -5,6 +5,8 @@ import (
 	"os"
 	"strings"
 	"text/template"
+
+	"github.com/luno/workflow/internal/util"
 )
 
 // CreateDiagram creates a diagram in a md file for communicating a workflow's set of steps in an easy-to-understand
@@ -39,21 +41,21 @@ func mermaidDiagram[Type any, Status StatusType](a API[Type, Status], path strin
 
 	graphInfo := w.statusGraph.Info()
 
-	var starting []string
+	var starting []int
 	for _, node := range graphInfo.StartingNodes {
-		starting = append(starting, statusToString(Status(node)))
+		starting = append(starting, node)
 	}
 
-	var terminal []string
+	var terminal []int
 	for _, node := range graphInfo.TerminalNodes {
-		terminal = append(terminal, statusToString(Status(node)))
+		terminal = append(terminal, node)
 	}
 
 	var transitions []MermaidTransition
 	for _, transition := range graphInfo.Transitions {
 		transitions = append(transitions, MermaidTransition{
-			From: statusToString(Status(transition.From)),
-			To:   statusToString(Status(transition.To)),
+			From: transition.From,
+			To:   transition.To,
 		})
 	}
 
@@ -63,22 +65,25 @@ func mermaidDiagram[Type any, Status StatusType](a API[Type, Status], path strin
 		StartingPoints: starting,
 		TerminalPoints: terminal,
 		Transitions:    transitions,
+		Nodes:          w.statusGraph.Nodes(),
 	}
 
-	return template.Must(template.New("").Parse("```"+mermaidTemplate+"```")).Execute(file, mf)
+	return template.Must(template.New("").Funcs(map[string]any{
+		"Description": description[Status],
+	}).Parse("```"+mermaidTemplate+"```")).Execute(file, mf)
 }
 
-func statusToString[Status StatusType](s Status) string {
-	str := strings.ToLower(s.String())
-	str = strings.Replace(str, " ", "_", -1)
-	return str
+func description[Status StatusType](val int) string {
+	s := Status(val).String()
+	return util.CamelCaseToSpacing(s)
 }
 
 type MermaidFormat struct {
 	WorkflowName   string
 	Direction      MermaidDirection
-	StartingPoints []string
-	TerminalPoints []string
+	Nodes          []int
+	StartingPoints []int
+	TerminalPoints []int
 	Transitions    []MermaidTransition
 }
 
@@ -93,8 +98,8 @@ const (
 )
 
 type MermaidTransition struct {
-	From string
-	To   string
+	From int
+	To   int
 }
 
 var mermaidTemplate = `mermaid
@@ -103,6 +108,10 @@ title: Diagram of {{.WorkflowName}} Workflow
 ---
 stateDiagram-v2
 	direction {{.Direction}}
+	{{range $key, $value := .Nodes }}
+	{{$value}}: {{Description $value}}
+	{{- end }}
+
 	{{range $key, $value := .Transitions }}
 	{{$value.From}}-->{{$value.To}}
 	{{- end }}