CLOUDP-225849: add merging logic (#10)

tools/cli/go.mod

@@ -9,6 +9,7 @@ require (
 	github.com/stretchr/testify v1.9.0
 	github.com/tufin/oasdiff v1.10.11
 	go.uber.org/mock v0.4.0
+	golang.org/x/exp v0.0.0-20240119083558-1b970713d09a
 )
 
 require (

tools/cli/internal/openapi/errors/merge_conflict_error.go

@@ -0,0 +1,58 @@
+// Copyright 2024 MongoDB Inc
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package errors
+
+import "fmt"
+
+type ParamConflictError struct {
+	Entry string
+}
+
+func (e ParamConflictError) Error() string {
+	return fmt.Sprintf("there was a conflict with the Param component: %q", e.Entry)
+}
+
+type PathConflictError struct {
+	Entry string
+}
+
+func (e PathConflictError) Error() string {
+	return fmt.Sprintf("there was a conflict with the path: %q", e.Entry)
+}
+
+type ResponseConflictError struct {
+	Entry string
+}
+
+func (e ResponseConflictError) Error() string {
+	return fmt.Sprintf("there was a conflict on a the Response component: %q", e.Entry)
+}
+
+type SchemaConflictError struct {
+	Entry string
+}
+
+func (e SchemaConflictError) Error() string {
+	return fmt.Sprintf("there was a conflict on a Schema component: %q", e.Entry)
+}
+
+type TagConflictError struct {
+	Entry       string
+	Description string
+}
+
+func (e TagConflictError) Error() string {
+	return fmt.Sprintf("there was a conflict with the Tag %q with the description: %q", e.Entry, e.Description)
+}

tools/cli/internal/openapi/oasdiff.go

@@ -15,6 +15,8 @@
 package openapi
 
 import (
+	"log"
+
 	"github.com/mongodb/openapi/tools/cli/internal/openapi/errors"
 	"github.com/tufin/oasdiff/diff"
 	"github.com/tufin/oasdiff/load"
@@ -28,13 +30,42 @@ type OasDiff struct {
 	parser   Parser
 }
 
-func (o OasDiff) mergeSpecIntoBase() error {
-	return o.mergePaths()
+func (o OasDiff) mergeSpecIntoBase() (*load.SpecInfo, error) {
+	if o.external == nil || o.external.Spec == nil {
+		return o.base, nil
+	}
+
+	if o.base == nil || o.base.Spec == nil {
+		return o.external, nil
+	}
+
+	if err := o.mergePaths(); err != nil {
+		return nil, err
+	}
+
+	if err := o.mergeTags(); err != nil {
+		return nil, err
+	}
+
+	if err := o.mergeComponents(); err != nil {
+		return nil, err
+	}
+
+	return o.base, nil
 }
 
 func (o OasDiff) mergePaths() error {
 	pathsToMerge := o.external.Spec.Paths
+	if pathsToMerge == nil || pathsToMerge.Len() == 0 {
+		return nil
+	}
+
 	basePaths := o.base.Spec.Paths
+	if basePaths == nil || basePaths.Len() == 0 {
+		o.base.Spec.Paths = pathsToMerge
+		return nil
+	}
+
 	for k, v := range pathsToMerge.Map() {
 		if ok := basePaths.Value(k); ok == nil {
 			basePaths.Set(k, v)
@@ -48,3 +79,161 @@ func (o OasDiff) mergePaths() error {
 	o.base.Spec.Paths = basePaths
 	return nil
 }
+
+func (o OasDiff) mergeTags() error {
+	tagsToMerge := o.external.Spec.Tags
+	if len(tagsToMerge) == 0 {
+		return nil
+	}
+
+	baseTags := o.base.Spec.Tags
+	if len(baseTags) == 0 {
+		o.base.Spec.Tags = tagsToMerge
+		return nil
+	}
+
+	tagsSet := make(map[string]bool, len(baseTags))
+	for _, v := range baseTags {
+		tagsSet[v.Name] = true
+	}
+
+	for _, v := range tagsToMerge {
+		if _, ok := tagsSet[v.Name]; !ok {
+			baseTags = append(baseTags, v)
+		} else {
+			return errors.TagConflictError{
+				Entry:       v.Name,
+				Description: v.Description,
+			}
+		}
+	}
+
+	o.base.Spec.Tags = baseTags
+	return nil
+}
+
+func (o OasDiff) mergeComponents() error {
+	if o.external.Spec.Components == nil {
+		return nil
+	}
+
+	if o.base.Spec.Components == nil {
+		o.base.Spec.Components = o.external.Spec.Components
+		return nil
+	}
+
+	if err := o.mergeParameters(); err != nil {
+		return err
+	}
+
+	if err := o.mergeResponses(); err != nil {
+		return err
+	}
+
+	return o.mergeSchemas()
+}
+
+func (o OasDiff) mergeParameters() error {
+	externalSpecParams := o.external.Spec.Components.Parameters
+	if len(externalSpecParams) == 0 {
+		return nil
+	}
+
+	baseParams := o.base.Spec.Components.Parameters
+	if len(baseParams) == 0 {
+		o.base.Spec.Components.Parameters = externalSpecParams
+		return nil
+	}
+	for k, v := range externalSpecParams {
+		if _, ok := baseParams[k]; !ok {
+			baseParams[k] = v
+		} else {
+			if o.areParamsIdentical(k) {
+				// if the responses are the same, we skip
+				log.Printf("\nWe silently resolved the conflict with the response %q because the definition was identical.\n", k)
+				continue
+			}
+
+			// The params have the same name but different definitions
+			return errors.ParamConflictError{
+				Entry: k,
+			}
+		}
+	}
+
+	o.base.Spec.Components.Parameters = baseParams
+	return nil
+}
+
+func (o OasDiff) mergeResponses() error {
+	extResponses := o.external.Spec.Components.Responses
+	if len(extResponses) == 0 {
+		return nil
+	}
+
+	baseResponses := o.base.Spec.Components.Responses
+	if len(baseResponses) == 0 {
+		o.base.Spec.Components.Responses = extResponses
+		return nil
+	}
+
+	for k, v := range extResponses {
+		if _, ok := baseResponses[k]; !ok {
+			baseResponses[k] = v
+		} else {
+			if o.areResponsesIdentical(k) {
+				// if the params are the same, we skip
+				log.Printf("\nWe silently resolved the conflict with the params %q because the definition was identical.\n", k)
+				continue
+			}
+
+			// The responses have the same name but different definitions
+			return errors.ResponseConflictError{
+				Entry: k,
+			}
+		}
+	}
+
+	o.base.Spec.Components.Responses = baseResponses
+	return nil
+}
+
+func (o OasDiff) mergeSchemas() error {
+	extSchemas := o.external.Spec.Components.Schemas
+	baseSchemas := o.base.Spec.Components.Schemas
+
+	for k, schemaToMerge := range extSchemas {
+		if _, ok := baseSchemas[k]; !ok {
+			baseSchemas[k] = schemaToMerge
+		} else {
+			if o.areSchemaIdentical(k) {
+				// if the schemas are the same, we skip
+				log.Printf("\nWe silently resolved the conflict with the schemas %q because the definition was identical.\n", k)
+				continue
+			}
+
+			// The schemas have the same name but different definitions
+			return errors.SchemaConflictError{
+				Entry: k,
+			}
+		}
+	}
+
+	o.base.Spec.Components.Schemas = baseSchemas
+	return nil
+}
+
+func (o OasDiff) areParamsIdentical(paramName string) bool {
+	_, ok := o.specDiff.ParametersDiff.Modified[paramName]
+	return !ok
+}
+
+func (o OasDiff) areResponsesIdentical(name string) bool {
+	_, ok := o.specDiff.ResponsesDiff.Modified[name]
+	return !ok
+}
+
+func (o OasDiff) areSchemaIdentical(name string) bool {
+	_, ok := o.specDiff.SchemasDiff.Modified[name]
+	return !ok
+}