fix: add command executor interface for better testing

Introduce the CommandExecutor interface to abstract command execution, 
allowing for easier mocking in tests. Implement DefaultCommandExecutor 
to use the os/exec package for executing commands. Update the 
GenerateCosmoRouterConfig function to utilize the new 
GenerateCosmoRouterConfigWithExecutor function that accepts a command 
executor parameter. Add a MockCommandExecutor for simulating command 
execution in unit tests with realistic behavior based on input YAML 
files. This enhances test coverage and simplifies error handling.
This commit is contained in:
2025-11-20 21:09:00 +01:00
parent df44ddbb8e
commit 47dbf827f2
2 changed files with 233 additions and 4 deletions
+22 -3
View File
@@ -11,9 +11,30 @@ import (
"gitlab.com/unboundsoftware/schemas/graph/model"
)
// CommandExecutor is an interface for executing external commands
// This allows for mocking in tests
type CommandExecutor interface {
Execute(name string, args ...string) ([]byte, error)
}
// DefaultCommandExecutor implements CommandExecutor using os/exec
type DefaultCommandExecutor struct{}
// Execute runs a command and returns its combined output
func (e *DefaultCommandExecutor) Execute(name string, args ...string) ([]byte, error) {
cmd := exec.Command(name, args...)
return cmd.CombinedOutput()
}
// GenerateCosmoRouterConfig generates a Cosmo Router execution config from subgraphs
// using the official wgc CLI tool via npx
func GenerateCosmoRouterConfig(subGraphs []*model.SubGraph) (string, error) {
return GenerateCosmoRouterConfigWithExecutor(subGraphs, &DefaultCommandExecutor{})
}
// GenerateCosmoRouterConfigWithExecutor generates a Cosmo Router execution config from subgraphs
// using the provided command executor (useful for testing)
func GenerateCosmoRouterConfigWithExecutor(subGraphs []*model.SubGraph, executor CommandExecutor) (string, error) {
if len(subGraphs) == 0 {
return "", fmt.Errorf("no subgraphs provided")
}
@@ -85,13 +106,11 @@ func GenerateCosmoRouterConfig(subGraphs []*model.SubGraph) (string, error) {
// Execute wgc router compose
// wgc is installed globally in the Docker image
outputFile := filepath.Join(tmpDir, "config.json")
cmd := exec.Command("wgc", "router", "compose",
output, err := executor.Execute("wgc", "router", "compose",
"--input", inputFile,
"--out", outputFile,
"--suppress-warnings",
)
output, err := cmd.CombinedOutput()
if err != nil {
return "", fmt.Errorf("wgc router compose failed: %w\nOutput: %s", err, string(output))
}
+211 -1
View File
@@ -2,14 +2,185 @@ package graph
import (
"encoding/json"
"fmt"
"os"
"strings"
"testing"
"github.com/stretchr/testify/assert"
"github.com/stretchr/testify/require"
"gopkg.in/yaml.v3"
"gitlab.com/unboundsoftware/schemas/graph/model"
)
// MockCommandExecutor implements CommandExecutor for testing
type MockCommandExecutor struct {
// CallCount tracks how many times Execute was called
CallCount int
// LastArgs stores the arguments from the last call
LastArgs []string
// Error can be set to simulate command failures
Error error
}
// Execute mocks the wgc command by generating a realistic config.json file
func (m *MockCommandExecutor) Execute(name string, args ...string) ([]byte, error) {
m.CallCount++
m.LastArgs = append([]string{name}, args...)
if m.Error != nil {
return nil, m.Error
}
// Parse the input file to understand what subgraphs we're composing
var inputFile, outputFile string
for i, arg := range args {
if arg == "--input" && i+1 < len(args) {
inputFile = args[i+1]
}
if arg == "--out" && i+1 < len(args) {
outputFile = args[i+1]
}
}
if inputFile == "" || outputFile == "" {
return nil, fmt.Errorf("missing required arguments")
}
// Read the input YAML to get subgraph information
inputData, err := os.ReadFile(inputFile)
if err != nil {
return nil, fmt.Errorf("failed to read input file: %w", err)
}
var input struct {
Version int `yaml:"version"`
Subgraphs []struct {
Name string `yaml:"name"`
RoutingURL string `yaml:"routing_url,omitempty"`
Schema map[string]string `yaml:"schema"`
Subscription map[string]interface{} `yaml:"subscription,omitempty"`
} `yaml:"subgraphs"`
}
if err := yaml.Unmarshal(inputData, &input); err != nil {
return nil, fmt.Errorf("failed to parse input YAML: %w", err)
}
// Generate a realistic Cosmo Router config based on the input
config := map[string]interface{}{
"version": "mock-version-uuid",
"subgraphs": func() []map[string]interface{} {
subgraphs := make([]map[string]interface{}, len(input.Subgraphs))
for i, sg := range input.Subgraphs {
subgraph := map[string]interface{}{
"id": fmt.Sprintf("mock-id-%d", i),
"name": sg.Name,
}
if sg.RoutingURL != "" {
subgraph["routingUrl"] = sg.RoutingURL
}
subgraphs[i] = subgraph
}
return subgraphs
}(),
"engineConfig": map[string]interface{}{
"graphqlSchema": generateMockSchema(input.Subgraphs),
"datasourceConfigurations": func() []map[string]interface{} {
dsConfigs := make([]map[string]interface{}, len(input.Subgraphs))
for i, sg := range input.Subgraphs {
// Read SDL from file
sdl := ""
if schemaFile, ok := sg.Schema["file"]; ok {
if sdlData, err := os.ReadFile(schemaFile); err == nil {
sdl = string(sdlData)
}
}
dsConfig := map[string]interface{}{
"id": fmt.Sprintf("datasource-%d", i),
"kind": "GRAPHQL",
"customGraphql": map[string]interface{}{
"federation": map[string]interface{}{
"enabled": true,
"serviceSdl": sdl,
},
"subscription": func() map[string]interface{} {
if len(sg.Subscription) > 0 {
return map[string]interface{}{
"enabled": true,
"url": map[string]interface{}{
"staticVariableContent": sg.Subscription["url"],
},
"protocol": sg.Subscription["protocol"],
"websocketSubprotocol": sg.Subscription["websocket_subprotocol"],
}
}
return map[string]interface{}{
"enabled": false,
}
}(),
},
}
dsConfigs[i] = dsConfig
}
return dsConfigs
}(),
},
}
// Write the config to the output file
configJSON, err := json.Marshal(config)
if err != nil {
return nil, fmt.Errorf("failed to marshal config: %w", err)
}
if err := os.WriteFile(outputFile, configJSON, 0o644); err != nil {
return nil, fmt.Errorf("failed to write output file: %w", err)
}
return []byte("Success"), nil
}
// generateMockSchema creates a simple merged schema from subgraphs
func generateMockSchema(subgraphs []struct {
Name string `yaml:"name"`
RoutingURL string `yaml:"routing_url,omitempty"`
Schema map[string]string `yaml:"schema"`
Subscription map[string]interface{} `yaml:"subscription,omitempty"`
},
) string {
schema := strings.Builder{}
schema.WriteString("schema {\n query: Query\n")
// Check if any subgraph has subscriptions
hasSubscriptions := false
for _, sg := range subgraphs {
if len(sg.Subscription) > 0 {
hasSubscriptions = true
break
}
}
if hasSubscriptions {
schema.WriteString(" subscription: Subscription\n")
}
schema.WriteString("}\n\n")
// Add types by reading SDL files
for _, sg := range subgraphs {
if schemaFile, ok := sg.Schema["file"]; ok {
if sdlData, err := os.ReadFile(schemaFile); err == nil {
schema.WriteString(string(sdlData))
schema.WriteString("\n")
}
}
}
return schema.String()
}
func TestGenerateCosmoRouterConfig(t *testing.T) {
tests := []struct {
name string
@@ -232,16 +403,28 @@ func TestGenerateCosmoRouterConfig(t *testing.T) {
for _, tt := range tests {
t.Run(tt.name, func(t *testing.T) {
config, err := GenerateCosmoRouterConfig(tt.subGraphs)
// Use mock executor for all tests
mockExecutor := &MockCommandExecutor{}
config, err := GenerateCosmoRouterConfigWithExecutor(tt.subGraphs, mockExecutor)
if tt.wantErr {
assert.Error(t, err)
// Verify executor was not called for error cases
if len(tt.subGraphs) == 0 {
assert.Equal(t, 0, mockExecutor.CallCount, "Should not call executor for empty subgraphs")
}
return
}
require.NoError(t, err)
assert.NotEmpty(t, config, "Config should not be empty")
// Verify executor was called correctly
assert.Equal(t, 1, mockExecutor.CallCount, "Should call executor once")
assert.Equal(t, "wgc", mockExecutor.LastArgs[0], "Should call wgc command")
assert.Contains(t, mockExecutor.LastArgs, "router", "Should include 'router' arg")
assert.Contains(t, mockExecutor.LastArgs, "compose", "Should include 'compose' arg")
if tt.validate != nil {
tt.validate(t, config)
}
@@ -249,6 +432,33 @@ func TestGenerateCosmoRouterConfig(t *testing.T) {
}
}
// TestGenerateCosmoRouterConfig_MockError tests error handling with mock executor
func TestGenerateCosmoRouterConfig_MockError(t *testing.T) {
subGraphs := []*model.SubGraph{
{
Service: "test-service",
URL: stringPtr("http://localhost:4001/query"),
Sdl: "type Query { test: String }",
},
}
// Create a mock executor that returns an error
mockExecutor := &MockCommandExecutor{
Error: fmt.Errorf("simulated wgc failure"),
}
config, err := GenerateCosmoRouterConfigWithExecutor(subGraphs, mockExecutor)
// Verify error is propagated
assert.Error(t, err)
assert.Contains(t, err.Error(), "wgc router compose failed")
assert.Contains(t, err.Error(), "simulated wgc failure")
assert.Empty(t, config)
// Verify executor was called
assert.Equal(t, 1, mockExecutor.CallCount, "Should have attempted to call executor")
}
// Helper function for tests
func stringPtr(s string) *string {
return &s