pkg/workflows/sdk: add WorkflowSpec.FormatChart for mermaid flowcharts

Author: jmank88

Makefile

@@ -47,3 +47,7 @@ lint-workspace:
 
 lint:
 	@./script/lint.sh $(GOLANGCI_LINT_VERSION) "$(GOLANGCI_LINT_COMMON_OPTS)" $(GOLANGCI_LINT_DIRECTORY) "--new-from-rev=origin/main"
+
+.PHONY: test-quiet
+test-quiet:
+	go test ./... | grep -v "\[no test files\]" | grep -v "\(cached\)"

go.mod

@@ -1,8 +1,6 @@
 module github.com/smartcontractkit/chainlink-common
 
-go 1.22.0
-
-toolchain go1.22.7
+go 1.23
 
 require (
 	github.com/andybalholm/brotli v1.1.0

pkg/capabilities/capabilities.go

@@ -1,6 +1,7 @@
 package capabilities
 
 import (
+	"cmp"
 	"context"
 	"fmt"
 	"regexp"
@@ -53,6 +54,26 @@ func (c CapabilityType) IsValid() error {
 	return fmt.Errorf("invalid capability type: %s", c)
 }
 
+func (c CapabilityType) cmpOrder() int {
+	switch c {
+	case CapabilityTypeTrigger:
+		return 0
+	case CapabilityTypeAction:
+		return 1
+	case CapabilityTypeConsensus:
+		return 2
+	case CapabilityTypeTarget:
+		return 3
+	case CapabilityTypeUnknown:
+		return 4
+	default:
+		return 5
+	}
+}
+func (c CapabilityType) Compare(c2 CapabilityType) int {
+	return cmp.Compare(c.cmpOrder(), c2.cmpOrder())
+}
+
 // CapabilityResponse is a struct for the Execute response of a capability.
 type CapabilityResponse struct {
 	Value *values.Map

pkg/workflows/dependency_graph.go

@@ -129,7 +129,7 @@ func BuildDependencyGraph(spec sdk.WorkflowSpec) (*DependencyGraph, error) {
 		Graph:    g,
 		Triggers: triggerSteps,
 	}
-	return wf, err
+	return wf, nil
 }
 
 var (

pkg/workflows/dependency_graph_chart.go

@@ -0,0 +1,73 @@
+package workflows
+
+import (
+	"cmp"
+	"fmt"
+	"maps"
+	"slices"
+	"strings"
+	"text/template"
+
+	"github.com/smartcontractkit/chainlink-common/pkg/workflows/sdk"
+)
+
+func (g *DependencyGraph) FormatChart() (string, error) {
+	var sb strings.Builder
+	steps := slices.Clone(g.Spec.Triggers)
+	steps = append(steps, g.Spec.Steps()...)
+	slices.SortFunc(steps, func(a, b sdk.StepDefinition) int {
+		return cmp.Or(
+			a.CapabilityType.Compare(b.CapabilityType),
+			cmp.Compare(a.Ref, b.Ref),
+			cmp.Compare(a.ID, b.ID),
+		)
+	})
+	preds, err := g.Graph.PredecessorMap()
+	if err != nil {
+		return "", fmt.Errorf("failed to get graph predecessors: %w", err)
+	}
+	type stepAndOutput struct {
+		Step   sdk.StepDefinition
+		Inputs []string
+	}
+	nodes := make([]stepAndOutput, len(steps))
+	for i, step := range steps {
+		nodes[i] = stepAndOutput{Step: step, Inputs: slices.Collect(maps.Keys(preds[step.Ref]))}
+	}
+	err = tmpl.Execute(&sb, nodes)
+	if err != nil {
+		return "", err
+	}
+	return sb.String(), nil
+}
+
+var tmpl = template.Must(template.New("").Funcs(map[string]any{
+	"replace": strings.ReplaceAll,
+}).Parse(`flowchart
+{{ range $i, $e := . }}
+	{{ $ref := .Step.Ref -}}
+	{{ $id := replace .Step.ID "@" "[at]" -}}
+	{{ $name := printf "%s<br><i>(%s)</i>" .Step.CapabilityType $id -}}
+	{{ if .Step.Ref -}}
+		{{ $name = printf "<b>%s</b><br>%s" .Step.Ref $name -}}
+	{{ else -}}
+		{{ $ref = printf "%s%d" "unnamed" $i -}}
+	{{ end -}}
+	{{ if eq .Step.CapabilityType "trigger" -}}
+	{{ $ref }}[\"{{$name}}"/]
+	{{ else if eq .Step.CapabilityType "consensus" -}}
+	{{ $ref }}[["{{$name}}"]]
+	{{ else if eq .Step.CapabilityType "target" -}}
+	{{ $ref }}[/"{{$name}}"\]
+	{{ else -}}
+	{{ $ref }}["{{$name}}"]
+	{{ end -}}
+	{{ if .Step.Inputs.OutputRef -}}
+	{{ .Step.Inputs.OutputRef }} --> {{ .Step.Ref }}
+	{{ else -}}
+		{{ range $out := .Inputs -}}
+	{{ $out }} --> {{ $ref }}
+		{{ end -}}
+	{{ end -}}
+{{ end -}}
+`))