feat(proxy): generate slugs

lib/schemaProxy.js

@@ -9,16 +9,21 @@
  * OF ANY KIND, either express or implied. See the License for the specific language
  * governing permissions and limitations under the License.
  */
+const ghslugger = require('github-slugger');
+
 const symbols = {
   pointer: Symbol('pointer'),
   filename: Symbol('filename'),
   id: Symbol('id'),
   titles: Symbol('titles'),
   resolve: Symbol('resolve'),
+  slug: Symbol('slug'),
 };
 
+const myslug = Symbol('myslug');
+
 const handler = ({
-  root = '', filename = '.', schemas, parent,
+  root = '', filename = '.', schemas, parent, slugger,
 }) => {
   const meta = {};
 
@@ -56,6 +61,19 @@ const handler = ({
     }
   };
 
+  meta[symbols.slug] = (target, prop, receiver) => {
+    if (!receiver[myslug] && !parent && receiver[symbols.filename]) {
+      receiver[myslug] = slugger.slug(receiver[symbols.filename].replace(/\..*$/, ''));
+    }
+    if (!receiver[myslug]) {
+      const parentslug = parent[symbols.slug];
+      const title = receiver.title;
+      const name = receiver[symbols.pointer].split('/').pop();
+      receiver[myslug] = slugger.slug(parentslug + '-' + (title ? title : name));
+    }
+    return receiver[myslug];
+  };
+
   return {
     ownKeys: target => Reflect.ownKeys(target),
 
@@ -84,6 +102,7 @@ const handler = ({
           parent: receiver,
           filename,
           schemas,
+          slugger,
         }));
 
         if (subschema.$id) {
@@ -108,8 +127,10 @@ module.exports.loader = () => {
     known: {},
   };
 
+  const slugger = ghslugger();
+
   return (schema, filename) => {
-    const proxied = new Proxy(schema, handler({ filename, schemas }));
+    const proxied = new Proxy(schema, handler({ filename, schemas, slugger }));
     schemas.loaded.push(proxied);
     if (proxied.$id) {
       // stow away the schema for lookup

test/schemaProxy.test.js

@@ -13,7 +13,7 @@
 
 const assert = require('assert');
 const {
-  loader, pointer, filename, id, titles, resolve,
+  loader, pointer, filename, id, titles, resolve, slug,
 } = require('../lib/schemaProxy');
 
 const example = {
@@ -48,6 +48,10 @@ const example = {
       type: 'object',
       title: 'An object',
     },
+    zup: {
+      type: 'object',
+      title: 'An object',
+    },
     baz: {
       anyOf: [
         { $ref: '#/properties/foo' },
@@ -60,6 +64,7 @@ const example = {
 const referencing = {
   $schema: 'http://json-schema.org/draft-06/schema#',
   $id: 'https://example.com/schemas/referencing',
+  title: 'Referencing',
   properties: {
     $ref: 'https://example.com/schemas/example#/properties',
     zap: {
@@ -142,7 +147,25 @@ describe('Testing Schema Proxy', () => {
 
     assert.deepStrictEqual(new Set(Object.keys(proxied2.properties)), new Set([
       '$ref', 'zap', // the two properties from the original declaration
-      'foo', 'bar', 'zip', 'baz', // plus all the referenced properties
+      'foo', 'bar', 'zip', 'zup', 'baz', // plus all the referenced properties
     ]));
   });
+
+  it('Schema proxy generates unique names', () => {
+    const myloader = loader();
+    const proxied1 = myloader(example, 'example.schema.json');
+    const proxied2 = myloader(referencing, 'referencing.schema.json');
+    const proxied3 = myloader({
+      title: 'Referencing'
+    }, 'anotherreference.schema.json');
+
+    assert.equal(proxied1[slug], 'example');
+
+    assert.equal(proxied1.properties.zip[slug], 'example-properties-an-object');
+    assert.equal(proxied1.properties.zup[slug], 'example-properties-an-object-1'); //avoid duplicates
+
+    assert.equal(proxied2[slug], 'referencing');
+    assert.equal(proxied2[slug], 'referencing'); // make sure the slug stays stable
+    assert.equal(proxied3[slug], 'anotherreference'); 
+  });
 });