Feature/add contains filter

README.md

@@ -203,6 +203,41 @@ Add `_like` to filter (RegExp supported)
 GET /posts?title_like=server
 ```
 
+Add `_contains` to filter arrays attributes (case sensitive)
+
+```json
+{
+  "posts": [
+    { "id": 1, "title": "json-server", "author": "typicode", "tags": ["technology", "beginner"] },
+    { "id": 2, "title": "advanced json-server", "author": "typicode", "tags": ["technology-ai", "advanced"] }
+  ],
+  "comments": [
+    { "id": 1, "body": "some comment", "postId": 1 }
+  ],
+  "profile": { "name": "typicode" }
+}
+```
+
+```
+GET /posts?tags_contains=beginner
+```
+_returns [{ "id": 1, "title": "json-server", "author": "typicode", "tags": ["technology", "beginner"] }]_
+
+difference between __contains_ and __like_
+```
+GET /posts?tags_contains=technology
+```
+_returns [{ "id": 1, "title": "json-server", "author": "typicode", "tags": ["technology", "beginner"] }]_
+
+while __like_ returns both (_like does substring matching)
+
+_returns 
+[
+    { "id": 1, "title": "json-server", "author": "typicode", "tags": ["technology", "beginner"] },
+    { "id": 2, "title": "advanced json-server", "author": "typicode", "tags": ["technology-ai", "advanced"] }
+  ]
+_
+
 ### Full-text search
 
 Add `q`

src/server/router/plural.js

@@ -84,7 +84,8 @@ module.exports = (db, name, opts) => {
           /_lte$/.test(query) ||
           /_gte$/.test(query) ||
           /_ne$/.test(query) ||
-          /_like$/.test(query)
+          /_like$/.test(query) ||
+          /_contains$/.test(query)
         )
           return
       }
@@ -122,7 +123,8 @@ module.exports = (db, name, opts) => {
               const isDifferent = /_ne$/.test(key)
               const isRange = /_lte$/.test(key) || /_gte$/.test(key)
               const isLike = /_like$/.test(key)
-              const path = key.replace(/(_lte|_gte|_ne|_like)$/, '')
+              const isContains = /_contains$/.test(key)
+              const path = key.replace(/(_lte|_gte|_ne|_like|_contains)$/, '')
               // get item value based on path
               // i.e post.title -> 'foo'
               const elementValue = _.get(element, path)
@@ -138,13 +140,23 @@ module.exports = (db, name, opts) => {
                 return isLowerThan
                   ? value <= elementValue
                   : value >= elementValue
-              } else if (isDifferent) {
+              }
+
+              if (isDifferent) {
                 return value !== elementValue.toString()
-              } else if (isLike) {
+              }
+
+              if (isContains) {
+                let requested = _.filter((value || '').split(','), _.identity)
+                let found = _.intersection(elementValue, requested)
+                return _.isEqual(found, requested)
+              }
+
+              if (isLike) {
                 return new RegExp(value, 'i').test(elementValue.toString())
-              } else {
-                return value === elementValue.toString()
               }
+
+              return value === elementValue.toString()
             })
             .reduce((a, b) => a || b)
         })

test/server/plural.js

@@ -83,6 +83,13 @@ describe('Server', () => {
       { id: 15 }
     ]
 
+    db.products = [
+      { name: 'first product', bought_by: ['firstCustomer', 'secondCustomer'] },
+      { name: 'second product', bought_by: ['firstCustomer'] },
+      { name: 'third product', bought_by: ['secondCustomer'] },
+      { name: 'fourth product' }
+    ]
+
     server = jsonServer.create()
     router = jsonServer.router(db)
     server.use(jsonServer.defaults())
@@ -359,6 +366,22 @@ describe('Server', () => {
         .expect(200))
   })
 
+  describe('GET /:resource?attr_contains=', () => {
+    it('should respond with an array that matches the contains operator (case sensitive)', () =>
+      request(server)
+        .get('/products?bought_by_contains=firstCustomer')
+        .expect('Content-Type', /json/)
+        .expect([db.products[0], db.products[1]])
+        .expect(200))
+
+    it('should respond with an array that matches the contains operator when multiple contains (case sensitive)', () =>
+      request(server)
+        .get('/products?bought_by_contains=firstCustomer,secondCustomer')
+        .expect('Content-Type', /json/)
+        .expect([db.products[0]])
+        .expect(200))
+  })
+
   describe('GET /:parent/:parentId/:resource', () => {
     it('should respond with json and corresponding nested resources', () =>
       request(server)