feat: Add filter to remove unused views

tools/cli/internal/openapi/filter/extension.go

@@ -11,6 +11,7 @@
 // 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 filter
 
 import (
@@ -21,7 +22,7 @@ import (
 	"github.com/mongodb/openapi/tools/cli/internal/apiversion"
 )
 
-// Filter: ExtensionFilter is a filter that updates the x-sunset and x-xgen-version extensions to a date string
+// ExtensionFilter is a filter that updates the x-sunset and x-xgen-version extensions to a date string
 // and deletes the x-sunset extension if the latest matched version is deprecated by hidden versions
 // for the target environment
 type ExtensionFilter struct {

tools/cli/internal/openapi/filter/filter.go

@@ -11,6 +11,7 @@
 // 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 filter
 
 import (
@@ -55,6 +56,14 @@ func DefaultFilters(oas *openapi3.T, metadata *Metadata) []Filter {
 		&HiddenEnvsFilter{oas: oas, metadata: metadata},
 		&TagsFilter{oas: oas},
 		&OperationsFilter{oas: oas},
+		&SchemasFilter{oas: oas},
+	}
+}
+
+func FiltersToRemoveUnusedElements(oas *openapi3.T) []Filter {
+	return []Filter{
+		&TagsFilter{oas: oas},
+		&SchemasFilter{oas: oas},
 	}
 }
 

tools/cli/internal/openapi/filter/hidden_envs.go

@@ -11,6 +11,7 @@
 // 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 filter
 
 import (
@@ -25,7 +26,7 @@ const (
 	hiddenEnvsExtKey    = "envs"
 )
 
-// Filter: HiddenEnvsFilter is a filter that removes paths, operations,
+// HiddenEnvsFilter is a filter that removes paths, operations,
 // request/response bodies and content types that are hidden for the target environment
 type HiddenEnvsFilter struct {
 	oas      *openapi3.T

tools/cli/internal/openapi/filter/info.go

@@ -11,6 +11,7 @@
 // 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 filter
 
 import (
@@ -20,7 +21,7 @@ import (
 	"github.com/mongodb/openapi/tools/cli/internal/apiversion"
 )
 
-// Filter: InfoFilter is a filter that modifies the Info object in the OpenAPI spec.
+// InfoFilter is a filter that modifies the Info object in the OpenAPI spec.
 type InfoFilter struct {
 	oas      *openapi3.T
 	metadata *Metadata

tools/cli/internal/openapi/filter/operations.go

@@ -11,13 +11,14 @@
 // 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 filter
 
 import (
 	"github.com/getkin/kin-openapi/openapi3"
 )
 
-// Filter: OperationsFilter is a filter that removes the x-xgen-owner-team extension from operations
+// OperationsFilter is a filter that removes the x-xgen-owner-team extension from operations
 // and moves the x-sunset extension to the operation level.
 type OperationsFilter struct {
 	oas *openapi3.T

tools/cli/internal/openapi/filter/operations_test.go

@@ -11,6 +11,7 @@
 // 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 filter
 
 import (

tools/cli/internal/openapi/filter/schemas.go

@@ -0,0 +1,151 @@
+// Copyright 2025 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 filter
+
+import (
+	"encoding/json"
+	"fmt"
+	"github.com/getkin/kin-openapi/openapi3"
+	"strings"
+)
+
+// SchemasFilter removes tags that are not used in the operations.
+type SchemasFilter struct {
+	oas *openapi3.T
+}
+
+func (f *SchemasFilter) Apply() error {
+	if f.oas.Paths == nil {
+		return nil
+	}
+
+	usedRefs := map[string]bool{}
+	allRefs := findRefs(f.oas)
+
+	// Extract unique references used in the OpenAPI document
+	for ref := range allRefs {
+		refParts := strings.Split(ref, "/")
+		if len(refParts) >= 4 && refParts[1] == "components" && refParts[2] == "schemas" {
+			usedRefs[refParts[3]] = true
+		}
+	}
+
+	res2B, _ := json.Marshal(usedRefs)
+	fmt.Println("ANDREA:")
+	fmt.Println(string(res2B))
+
+	filterComponentSchemasInRefs(f.oas, usedRefs)
+	return nil
+}
+
+// findRefs returns all the ref included in an openapi spec
+func findRefs(oas *openapi3.T) map[string]bool {
+	if oas == nil {
+		return nil
+	}
+
+	refs := map[string]bool{}
+	for _, v := range oas.Paths.Map() {
+		refs[v.Ref] = true
+		for _, op := range v.Operations() {
+			for _, param := range op.Parameters {
+				refs[param.Ref] = true
+				findRefsSchemaRef(refs, param.Value.Schema)
+			}
+
+			if op.RequestBody != nil {
+				refs[op.RequestBody.Ref] = true
+				if op.RequestBody.Value != nil {
+					for _, content := range op.RequestBody.Value.Content {
+						if content.Schema != nil {
+							findRefsSchemaRef(refs, content.Schema)
+						}
+					}
+				}
+			}
+
+			for _, resp := range op.Responses.Map() {
+				refs[resp.Ref] = true
+				for _, content := range resp.Value.Content {
+					if content.Schema != nil {
+						findRefsSchemaRef(refs, content.Schema)
+					}
+				}
+			}
+		}
+
+	}
+
+	return refs
+}
+
+func findRefsSchemasRefs(refs map[string]bool, schemas openapi3.SchemaRefs) {
+	if schemas == nil {
+		return
+	}
+
+	for _, schema := range schemas {
+		if ok := refs[schema.Ref]; ok {
+			continue
+		}
+
+		refs[schema.Ref] = true
+		if schema.Value != nil {
+			findRefsSchemasRefs(refs, schema.Value.AllOf)
+			findRefsSchemasRefs(refs, schema.Value.OneOf)
+			findRefsSchemasRefs(refs, schema.Value.AnyOf)
+			findRefsSchemas(refs, schema.Value.Properties)
+		}
+	}
+}
+
+func findRefsSchemas(refs map[string]bool, schemas openapi3.Schemas) {
+	if schemas == nil {
+		return
+	}
+
+	for _, schema := range schemas {
+		findRefsSchemaRef(refs, schema)
+	}
+}
+
+func findRefsSchemaRef(refs map[string]bool, schema *openapi3.SchemaRef) {
+	if schema == nil {
+		return
+	}
+
+	refs[schema.Ref] = true
+	if schema.Value == nil {
+		return
+	}
+
+	findRefsSchemasRefs(refs, schema.Value.AllOf)
+	findRefsSchemasRefs(refs, schema.Value.OneOf)
+	findRefsSchemasRefs(refs, schema.Value.AnyOf)
+}
+
+func filterComponentSchemasInRefs(oas *openapi3.T, usedRefs map[string]bool) {
+	schemasToDelete := make([]string, 0)
+	for k, v := range oas.Components.Schemas {
+		fmt.Printf("k: %s, v: %v", k, v)
+		if ok := usedRefs[k]; !ok {
+			schemasToDelete = append(schemasToDelete, k)
+		}
+	}
+
+	for _, schemaToDelete := range schemasToDelete {
+		delete(oas.Components.Schemas, schemaToDelete)
+	}
+}

tools/cli/internal/openapi/filter/tags.go

@@ -11,6 +11,7 @@
 // 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 filter
 
 import (
@@ -19,7 +20,7 @@ import (
 	"github.com/getkin/kin-openapi/openapi3"
 )
 
-// Filter: TagsFilter removes tags that are not used in the operations.
+// TagsFilter removes tags that are not used in the operations.
 type TagsFilter struct {
 	oas *openapi3.T
 }

tools/cli/internal/openapi/filter/tags_test.go

@@ -11,6 +11,7 @@
 // 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 filter
 
 import (

tools/cli/internal/openapi/filter/versioning.go

@@ -11,6 +11,7 @@
 // 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 filter
 
 import (
@@ -21,7 +22,7 @@ import (
 	"github.com/mongodb/openapi/tools/cli/internal/apiversion"
 )
 
-// Filter: VersioningFilter is a filter that modifies the OpenAPI spec by removing operations and responses
+// VersioningFilter is a filter that modifies the OpenAPI spec by removing operations and responses
 // that are not supported by the target version.
 type VersioningFilter struct {
 	oas      *openapi3.T

tools/cli/internal/openapi/openapi.go

@@ -16,14 +16,15 @@ package openapi
 
 //go:generate mockgen -destination=../openapi/mock_openapi.go -package=openapi github.com/mongodb/openapi/tools/cli/internal/openapi Parser,Merger
 import (
+	"github.com/mongodb/openapi/tools/cli/internal/openapi/filter"
 	"log"
 
 	"github.com/getkin/kin-openapi/openapi3"
 	"github.com/tufin/oasdiff/diff"
 	"github.com/tufin/oasdiff/load"
 )
 
-// This struct is a 1-to-1 copy of the Spec struct in the openapi3 package.
+// Spec is a struct is a 1-to-1 copy of the Spec struct in the openapi3 package.
 // We need this to override the order of the fields in the struct.
 type Spec struct {
 	OpenAPI      string                        `json:"openapi" yaml:"openapi"`
@@ -63,6 +64,12 @@ func (o *OasDiff) MergeOpenAPISpecs(paths []string) (*Spec, error) {
 		}
 	}
 
+	for _, f := range filter.FiltersToRemoveUnusedElements(o.base.Spec) {
+		if err := f.Apply(); err != nil {
+			return nil, err
+		}
+	}
+
 	return newSpec(o.base.Spec), nil
 }
 

tools/cli/internal/openapi/openapi3.go

@@ -47,6 +47,7 @@ func (o *OpenAPI3) WithExcludedPrivatePaths() *OpenAPI3 {
 
 func (o *OpenAPI3) CreateOpenAPISpecFromPath(path string) (*load.SpecInfo, error) {
 	o.Loader.IsExternalRefsAllowed = o.IsExternalRefsAllowed
+
 	spec, err := load.NewSpecInfo(o.Loader, load.NewSource(path))
 	spec.Url = path
 	if err != nil {
@@ -56,6 +57,7 @@ func (o *OpenAPI3) CreateOpenAPISpecFromPath(path string) (*load.SpecInfo, error
 	if o.ExcludePrivatePaths {
 		removePrivatePaths(spec.Spec)
 	}
+
 	return spec, nil
 }