CLOUDP-257200: Add support to generate an yaml FOAS (#52)

Author: blva

tools/cli/go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/stretchr/testify v1.9.0
 	github.com/tufin/oasdiff v1.10.17
 	go.uber.org/mock v0.4.0
+	gopkg.in/yaml.v3 v3.0.1
 )
 
 require (
@@ -32,5 +33,4 @@ require (
 	github.com/wI2L/jsondiff v0.6.0 // indirect
 	github.com/yargevad/filepathx v1.0.0 // indirect
 	golang.org/x/text v0.15.0 // indirect
-	gopkg.in/yaml.v3 v3.0.1 // indirect
 )

tools/cli/internal/cli/flag/flag.go

@@ -21,4 +21,6 @@ const (
 	ExternalShort = "e"
 	Output        = "output"
 	OutputShort   = "o"
+	Format        = "format"
+	FormatShort   = "f"
 )

tools/cli/internal/cli/merge/merge.go

@@ -18,19 +18,22 @@ import (
 	"encoding/json"
 	"fmt"
 	"log"
+	"strings"
 
 	"github.com/mongodb/openapi/tools/cli/internal/cli/flag"
 	"github.com/mongodb/openapi/tools/cli/internal/cli/usage"
 	"github.com/mongodb/openapi/tools/cli/internal/openapi"
 	"github.com/spf13/afero"
 	"github.com/spf13/cobra"
+	"gopkg.in/yaml.v3"
 )
 
 type Opts struct {
 	Merger        openapi.Merger
 	fs            afero.Fs
 	basePath      string
 	outputPath    string
+	format        string
 	externalPaths []string
 }
 
@@ -62,12 +65,34 @@ func (o *Opts) PreRunE(_ []string) error {
 		return fmt.Errorf("no external OAS detected. Please, use the flag %s to include at least one OAS", flag.External)
 	}
 
+	if o.outputPath != "" && !strings.Contains(o.outputPath, ".json") && !strings.Contains(o.outputPath, ".yaml") {
+		return fmt.Errorf("output file must be either a JSON or YAML file, got %s", o.outputPath)
+	}
+
+	if o.format != "json" && o.format != "yaml" {
+		return fmt.Errorf("output format must be either 'json' or 'yaml', got %s", o.format)
+	}
+
 	m, err := openapi.NewOasDiff(o.basePath)
 	o.Merger = m
 	return err
 }
 
 func (o *Opts) saveFile(data []byte) error {
+	if strings.Contains(o.outputPath, ".yaml") || o.format == "yaml" {
+		var jsonData interface{}
+		if err := json.Unmarshal(data, &jsonData); err != nil {
+			return err
+		}
+
+		yamlData, err := yaml.Marshal(jsonData)
+		if err != nil {
+			return err
+		}
+
+		data = yamlData
+	}
+
 	if err := afero.WriteFile(o.fs, o.outputPath, data, 0o600); err != nil {
 		return err
 	}
@@ -98,5 +123,7 @@ func Builder() *cobra.Command {
 	cmd.Flags().StringVarP(&opts.basePath, flag.Base, flag.BaseShort, "", usage.Base)
 	cmd.Flags().StringArrayVarP(&opts.externalPaths, flag.External, flag.ExternalShort, nil, usage.External)
 	cmd.Flags().StringVarP(&opts.outputPath, flag.Output, flag.OutputShort, "", usage.Output)
+	cmd.Flags().StringVarP(&opts.format, flag.Format, flag.FormatShort, "json", usage.Format)
+
 	return cmd
 }

tools/cli/internal/cli/merge/merge_test.go

@@ -57,6 +57,37 @@ func TestSuccessfulMerge_Run(t *testing.T) {
 	}
 }
 
+func TestSuccessfulMergeYaml_Run(t *testing.T) {
+	ctrl := gomock.NewController(t)
+	mockMergerStore := openapi.NewMockMerger(ctrl)
+	fs := afero.NewMemMapFs()
+	externalPaths := []string{"external.json"}
+	opts := &Opts{
+		Merger:        mockMergerStore,
+		basePath:      "base.json",
+		outputPath:    "foas.yaml",
+		externalPaths: externalPaths,
+		fs:            fs,
+	}
+
+	response := &openapi.Spec{
+		OpenAPI: "v3.0.1",
+		Info:    &openapi3.Info{},
+		Servers: nil,
+		Tags:    openapi3.Tags{},
+	}
+
+	mockMergerStore.
+		EXPECT().
+		MergeOpenAPISpecs(opts.externalPaths).
+		Return(response, nil).
+		Times(1)
+
+	if err := opts.Run(); err != nil {
+		t.Fatalf("Run() unexpected error: %v", err)
+	}
+}
+
 func TestNoBaseSpecMerge_PreRun(t *testing.T) {
 	externalPaths := []string{"external.json"}
 	opts := &Opts{
@@ -101,8 +132,36 @@ func TestOpts_PreRunE(t *testing.T) {
 			o := &Opts{
 				basePath:      tt.basePath,
 				externalPaths: tt.externalPaths,
+				format:        "json",
 			}
 			tt.wantErr(t, o.PreRunE(nil))
 		})
 	}
 }
+
+func TestInvalidFormat_PreRun(t *testing.T) {
+	externalPaths := []string{"external.json"}
+	opts := &Opts{
+		outputPath:    "foas.json",
+		externalPaths: externalPaths,
+		basePath:      "base.json",
+		format:        "html",
+	}
+
+	err := opts.PreRunE(nil)
+	require.Error(t, err)
+	require.EqualError(t, err, "output format must be either 'json' or 'yaml', got html")
+}
+
+func TestInvalidPath_PreRun(t *testing.T) {
+	externalPaths := []string{"external.json"}
+	opts := &Opts{
+		outputPath:    "foas.html",
+		externalPaths: externalPaths,
+		basePath:      "base.json",
+	}
+
+	err := opts.PreRunE(nil)
+	require.Error(t, err)
+	require.EqualError(t, err, "output file must be either a JSON or YAML file, got foas.html")
+}

tools/cli/internal/cli/usage/usage.go

@@ -18,4 +18,5 @@ const (
 	Base     = "Base OAS. The command will merge other OASes into it."
 	External = "OASes that will be merged into the base OAS."
 	Output   = "File name where the command will store the output."
+	Format   = "Output format. Supported values are 'json' and 'yaml'."
 )

tools/cli/test/e2e/cli/merge_test.go

@@ -38,6 +38,32 @@ func TestMerge(t *testing.T) {
 		assert.Contains(t, o.String(), "\"ApiError\":")
 	})
 
+	t.Run("Merge valid specs to yaml", func(t *testing.T) {
+		base, err := NewBaseSpec()
+		require.NoError(t, err)
+		external, err := NewAPIRegistrySpec()
+		require.NoError(t, err)
+
+		cmd := exec.Command(cliPath,
+			"merge",
+			"-b",
+			base,
+			"-e",
+			external,
+			"-f",
+			"yaml",
+		)
+
+		var o, e bytes.Buffer
+		cmd.Stdout = &o
+		cmd.Stderr = &e
+		require.NoError(t, cmd.Run(), e.String())
+
+		assert.Contains(t, o.String(), "\"openapi\"")
+		assert.Contains(t, e.String(), "We silently resolved the conflict with the schemas \"ApiError\" because the definition was identical") //nolint:lll // Line is over 120 characters
+		assert.Contains(t, o.String(), "\"ApiError\":")
+	})
+
 	t.Run("Expecting Error: Merge duplicated path with base spec", func(t *testing.T) {
 		base, err := NewBaseSpec()
 		require.NoError(t, err)