Handled collation param for case insensitive indexes

README.md

@@ -234,6 +234,34 @@ Now in your query, you can specify a value for your discriminatorKey:
 
 and Feathers will automatically swap in the correct model and execute the query it instead of its parent model.
 
+## Collation Support
+
+This adapter includes support for [collation and case insensitive indexes available in MongoDB v3.4](https://docs.mongodb.com/manual/release-notes/3.4/#collation-and-case-insensitive-indexes). Collation parameters may be passed using the special `collation` parameter to the `find()`, `remove()` and `patch()` methods.
+
+### Example: Patch records with case-insensitive alphabetical ordering
+
+The example below would patch all student records with grades of `'c'` or `'C'` and above (a natural language ordering). Without collations this would not be as simple, since the comparison `{ $gt: 'c' }` would not include uppercase grades of `'C'` because the code point of `'C'` is less than that of `'c'`.
+
+```js
+const patch = { shouldStudyMore: true };
+const query = { grade: { $gte: 'c' } };
+const collation = { locale: 'en', strength: 1 };
+students.patch(null, patch, { query, collation }).then( ... );
+```
+
+### Example: Find records with a case-insensitive search
+
+Similar to the above example, this would find students with a grade of `'c'` or greater, in a case-insensitive manner.
+
+```js
+const query = { grade: { $gte: 'c' } };
+const collation = { locale: 'en', strength: 1 };
+students.find({ query, collation }).then( ... );
+```
+
+For more information on MongoDB's collation feature, visit the [collation reference page](https://docs.mongodb.com/manual/reference/collation/).
+
+
 ## License
 
 [MIT](LICENSE)

lib/service.js

@@ -61,6 +61,11 @@ class Service {
       q.sort(filters.$sort);
     }
 
+    // Handle collation
+    if (params.collation) {
+      q.collation(params.collation);
+    }
+
     // Handle $limit
     if (typeof filters.$limit !== 'undefined') {
       q.limit(filters.$limit);
@@ -232,6 +237,10 @@ class Service {
     const query = Object.assign({}, filterQuery(params.query || {}).query);
     const mapIds = page => page.data.map(current => current[this.id]);
 
+    if (params.collation) {
+      query.collation = params.collation;
+    }
+
     // By default we will just query for the one id. For multi patch
     // we create a list of the ids of all items that will be changed
     // to re-query them after the update
@@ -303,6 +312,10 @@ class Service {
   remove (id, params) {
     const query = Object.assign({}, filterQuery(params.query || {}).query);
 
+    if (params.collation) {
+      query.collation = params.collation;
+    }
+
     if (id !== null) {
       query[this.id] = id;
     }

test/error-handler.test.js

@@ -82,7 +82,7 @@ describe('Feathers Mongoose Error Handler', () => {
   });
 
   it('wraps a VersionError as a BadRequest', done => {
-    let e = new mongoose.Error.VersionError({ _id: 'testing' });
+    let e = new mongoose.Error.VersionError({ _id: 'testing' }, null, []);
     errorHandler(e).catch(error => {
       expect(error).to.be.an.instanceof(errors.BadRequest);
       done();

test/index.test.js

@@ -99,6 +99,98 @@ describe('Feathers Mongoose Service', () => {
     });
   });
 
+  describe('Special collation param', () => {
+    function indexOfName (results, name) {
+      let index;
+      results.every(function (person, i) {
+        if (person.name === name) {
+          index = i;
+          return false;
+        }
+        return true;
+      });
+      return index;
+    }
+
+    beforeEach(() => {
+      return people.remove(null, {}).then(() => {
+        return people.create([
+          { name: 'AAA' },
+          { name: 'aaa' },
+          { name: 'ccc' }
+        ]);
+      });
+    });
+
+    it('sorts with default behavior without collation param', () => {
+      return people.find({ query: { $sort: { name: -1 } } }).then(r => {
+        expect(indexOfName(r, 'aaa')).to.be.below(indexOfName(r, 'AAA'));
+      });
+    });
+
+    it('sorts using collation param if present', () => {
+      return people
+        .find({
+          query: { $sort: { name: -1 } },
+          collation: { locale: 'en', strength: 1 }
+        })
+        .then(r => {
+          expect(indexOfName(r, 'AAA')).to.be.below(indexOfName(r, 'aaa'));
+        });
+    });
+
+    it('removes with default behavior without collation param', () => {
+      return people
+        .remove(null, { query: { name: { $gt: 'AAA' } } })
+        .then(() => {
+          return people.find().then(r => {
+            expect(r).to.have.lengthOf(1);
+            expect(r[0].name).to.equal('AAA');
+          });
+        });
+    });
+
+    it('removes using collation param if present', () => {
+      return people
+        .remove(null, {
+          query: { name: { $gt: 'AAA' } },
+          collation: { locale: 'en', strength: 1 }
+        })
+        .then(() => {
+          return people.find().then(r => {
+            expect(r).to.have.lengthOf(3);
+          });
+        });
+    });
+
+    it('updates with default behavior without collation param', () => {
+      const query = { name: { $gt: 'AAA' } };
+
+      return people.patch(null, { age: 99 }, { query }).then(r => {
+        expect(r).to.have.lengthOf(2);
+        r.forEach(person => {
+          expect(person.age).to.equal(99);
+        });
+      });
+    });
+
+    it('updates using collation param if present', () => {
+      return people
+        .patch(
+          null,
+          { age: 110 },
+        {
+          query: { name: { $gt: 'AAA' } },
+          collation: { locale: 'en', strength: 1 }
+        }
+        )
+        .then(r => {
+          expect(r).to.have.lengthOf(1);
+          expect(r[0].name).to.equal('ccc');
+        });
+    });
+  });
+
   describe('Common functionality', () => {
     beforeEach(() => {
       // FIXME (EK): This is shit. We should be loading fixtures