limit to only mapping when asked to and fix non-uniq mappings

src/services/models/Schema.ts

@@ -1,12 +1,8 @@
 import { action, observable } from 'mobx';
 
-import { OpenAPIExternalDocumentation, OpenAPISchema, Referenced } from '../../types';
-
-import { OpenAPIParser } from '../OpenAPIParser';
-import { RedocNormalizedOptions } from '../RedocNormalizedOptions';
-import { FieldModel } from './Field';
-
 import { MergedOpenAPISchema } from '../';
+
+import { OpenAPIExternalDocumentation, OpenAPISchema, Referenced } from '../../types';
 import {
   detectType,
   extractExtensions,
@@ -21,6 +17,10 @@ import {
 
 import { l } from '../Labels';
 
+import { OpenAPIParser } from '../OpenAPIParser';
+import { RedocNormalizedOptions } from '../RedocNormalizedOptions';
+import { FieldModel } from './Field';
+
 // TODO: refactor this model, maybe use getters instead of copying all the values
 export class SchemaModel {
   pointer: string;
@@ -216,29 +216,52 @@ export class SchemaModel {
   ) {
     const discriminator = getDiscriminator(schema)!;
     this.discriminatorProp = discriminator.propertyName;
-    const derived = parser.findDerived([...(schema.parentRefs || []), this.pointer]);
+    let derived: Dict<string> = {};
+
+    const mapping = discriminator.mapping || {};
+    // Defines if the mapping is exhaustive. This avoids having references
+    // that overlap with the mapping entries
+    let isLimitedToMapping = discriminator['x-limitToMapping'] || false;
+    // if there are no mappings, assume non-exhaustive
+    if (Object.keys(mapping).length === 0) {
+      isLimitedToMapping = false;
+    }
+
+    // when non-exhaustive, search for implicit references
+    if (!isLimitedToMapping) {
+      derived = parser.findDerived([...(schema.parentRefs || []), this.pointer]);
 
       if (schema.oneOf) {
         for (const variant of schema.oneOf) {
           if (variant.$ref === undefined) {
             continue;
           }
-        const name = JsonPointer.baseName(variant.$ref);
+          derived[variant.$ref] = JsonPointer.baseName(variant.$ref);
-        derived[variant.$ref] = name;
+        }
       }
     }
 
-    const mapping = discriminator.mapping || {};
+    // concatenate the implict refs with the mapping ones
-    for (const name in mapping) {
+    const mappingOneOf = Object.keys(mapping).map(name => {
-      derived[mapping[name]] = name;
+      const ref = mapping[name];
+
+      // do not include implicit refs in the list when we have a mapped one
+      if (ref in derived) {
+        delete derived[ref];
       }
 
-    const refs = Object.keys(derived);
+      const innerSchema = new SchemaModel(parser, parser.byRef(ref)!, ref, this.options, true);
-    this.oneOf = refs.map(ref => {
+      innerSchema.title = name;
+      return innerSchema;
+    });
+
+    this.oneOf = mappingOneOf.concat(
+      Object.keys(derived).map(ref => {
         const innerSchema = new SchemaModel(parser, parser.byRef(ref)!, ref, this.options, true);
         innerSchema.title = derived[ref];
         return innerSchema;
-    });
+      }),
+    );
   }
 }
 

src/types/open-api.d.ts

@@ -144,6 +144,7 @@ export interface OpenAPISchema {
 export interface OpenAPIDiscriminator {
   propertyName: string;
   mapping?: { [name: string]: string };
+  'x-limitToMapping'?: boolean;
 }
 
 export interface OpenAPIMediaType {