Merge pull request #3 from lever/fix/snapshot-queries

Handle projections, queries on Mongo doc properties (like _id) and fix comparisons to null

Author: ericyhwang

.travis.yml

@@ -1,8 +1,9 @@
 language: node_js
 node_js:
-  - 5
+  - 9
+  - 8
+  - 6
   - 4
-  - 0.10
 script: "npm run test-cover"
 # Send coverage data to Coveralls
 after_script: "cat ./coverage/lcov.info | ./node_modules/coveralls/bin/coveralls.js"

index.js

@@ -1,5 +1,14 @@
 var Mingo = require('mingo');
 
+// Snapshot properties added to the root doc by `castToDoc()` in sharedb-mongo
+var MONGO_DOC_PROPERTIES = {
+  '_id': 'id',
+  '_v': 'v',
+  '_type': 'type',
+  '_m': 'm',
+  '_o': 'o'
+};
+
 function extendMemoryDB(MemoryDB) {
   function ShareDBMingo(options) {
     if (!(this instanceof ShareDBMingo)) return new ShareDBMingo(options);
@@ -10,8 +19,11 @@ function extendMemoryDB(MemoryDB) {
 
   ShareDBMingo.prototype._querySync = function(snapshots, query, options) {
     var parsed = parseQuery(query);
+    var mingoQuery = new Mingo.Query(castToSnapshotQuery(parsed.query));
 
-    var filtered = filter(snapshots, parsed.query);
+    var filtered = snapshots.filter(function(snapshot) {
+      return mingoQuery.test(snapshot);
+    });
     if (parsed.sort) sort(filtered, parsed.sort);
     if (parsed.skip) filtered.splice(0, parsed.skip);
     if (parsed.limit) filtered = filtered.slice(0, parsed.limit);
@@ -23,11 +35,11 @@ function extendMemoryDB(MemoryDB) {
   };
 
   ShareDBMingo.prototype.queryPollDoc = function(collection, id, query, options, callback) {
-    var mingoQuery = new Mingo.Query(query);
+    var mingoQuery = new Mingo.Query(castToSnapshotQuery(query));
     this.getSnapshot(collection, id, null, null, function(err, snapshot) {
       if (err) return callback(err);
       if (snapshot.data) {
-        callback(null, mingoQuery.test(snapshot.data));
+        callback(null, mingoQuery.test(snapshot));
       } else {
         callback(null, false);
       }
@@ -71,12 +83,29 @@ function extendMemoryDB(MemoryDB) {
     };
   }
 
-  // Support exact key match filters only
-  function filter(snapshots, query) {
-    var mingoQuery = new Mingo.Query(query);
-    return snapshots.filter(function(snapshot) {
-      return snapshot.data && mingoQuery.test(snapshot.data);
-    });
+  // Build a query object that mimics how the query would be executed if it were
+  // made against snapshots persisted with `sharedb-mongo`
+  // FIXME: This doesn't handle nested doc properties with dots like: {'_m.mtime': 12300}
+  function castToSnapshotQuery(query) {
+    var snapshotQuery = {};
+    for (var property in query) {
+      // Mongo doc property
+      if (MONGO_DOC_PROPERTIES[property]) {
+        snapshotQuery[MONGO_DOC_PROPERTIES[property]] = query[property];
+
+      // top-level boolean operator
+      } else if (property[0] === '$' && Array.isArray(query[property])) {
+        snapshotQuery[property] = [];
+        for (var i = 0; i < query[property].length; i++) {
+          snapshotQuery[property].push(castToSnapshotQuery(query[property][i]));
+        }
+
+      // nested `data` document
+      } else {
+        snapshotQuery["data." + property] = query[property];
+      }
+    }
+    return snapshotQuery;
   }
 
   // Support sorting with the Mongo $orderby syntax

package.json

@@ -25,7 +25,7 @@
   },
   "homepage": "https://github.com/share/sharedb-mingo-memory#readme",
   "dependencies": {
-    "mingo": "^0.6.3",
+    "mingo": "^2.2.0",
     "sharedb": "^1.0.0-beta"
   }
 }

test/query.js

@@ -50,7 +50,94 @@ module.exports = function() {
     });
   });
 
-  describe('top-level boolean operator', function(done) {
+  describe('filtering on special Share properties', function() {
+    // When sharedb-mongo persists a snapshot into Mongo, any properties
+    // underneath `data` get "promoted" to top-level, and Share properties
+    // get underscore-prefixed to avoid name conflicts, like `v` to `_v`.
+    //
+    // Query conditions don't undergo this transformation, so if you wanted
+    // to filter on snapshot version, you'd query with `{_v: 12}`. These tests
+    // check that sharedb-mingo-memory is consistent with sharedb-mongo for
+    // queries like those that filter on non-data Share properties.
+    var snapshots = [
+      {type: 'json0', v: 1, data: {x: 1, y: 1}, id: "test1", m: {mtime: 1000}},
+      {type: 'json0', v: 1, data: {x: 1, y: 2}, id: "test2", m: {mtime: 1001}},
+      {type: 'json0', v: 1, data: {x: 2, y: 2}, id: "test3", m: {mtime: 1002}}
+    ];
+    var snapshotsNoMeta = snapshots.map(function(snapshot) {
+      var snapshotCopy = JSON.parse(JSON.stringify(snapshot));
+      delete snapshotCopy.m;
+      return snapshotCopy;
+    });
+
+    beforeEach(function(done) {
+      var db = this.db;
+      async.each(snapshots, function(snapshot, cb) {
+        db.commit('testcollection', snapshot.id, {v: 0, create: {}}, snapshot, null, cb);
+      }, done);
+    });
+
+    it('condition on Mongo _id (Share id)', function(done) {
+      this.db.query('testcollection', {_id: 'test1'}, null, null, function(err, results, extra) {
+        if (err) throw err;
+        expect(results).eql([snapshotsNoMeta[0]]);
+        done();
+      });
+    });
+
+    // The simpler query-casting approach doesn't handle queries that filter on
+    // sub-properties of the Share metadata object. An alternative would be to
+    // rewrite this module to cast Share snapshots to Mongo docs and vice versa,
+    // the same way that sharedb-mongo does:
+    // https://github.com/share/sharedb-mingo-memory/pull/3#pullrequestreview-99017385
+    it.skip('condition on sub-property under Share metadata', function(done) {
+      this.db.query('testcollection', {'_m.mtime': 1001}, null, null, function(err, results, extra) {
+        if (err) throw err;
+        expect(results).eql([snapshotsNoMeta[1]]);
+        done();
+      });
+    });
+
+    it('condition on Mongo _id and Share data', function(done) {
+      this.db.query('testcollection', {y: 2, _id: {$nin: ['test2']}}, null, null, function(err, results, extra) {
+        if (err) throw err;
+        expect(results).eql([snapshotsNoMeta[2]]);
+        done();
+      });
+    });
+
+    it('top-level boolean operator', function(done) {
+      this.db.query('testcollection', {$or: [{y: 1}, {_id: 'test2'}]}, null, null, function(err, results, extra) {
+        if (err) throw err;
+        expect(results).eql([snapshotsNoMeta[0], snapshotsNoMeta[1]]);
+        done();
+      });
+    });
+  });
+
+  it('filters with null condition', function(done) {
+    var snapshots = [
+      {type: 'json0', v: 1, data: {x: 1, y: 1}, id: "test1"},
+      {type: 'json0', v: 1, data: {x: 1}, id: "test2"}, // y value intentionally omitted
+      {type: 'json0', v: 1, data: {x: 2, y: 2}, id: "test3"}
+    ];
+    var query = {y: null};
+
+    var db = this.db;
+    async.each(snapshots, function(snapshot, cb) {
+      db.commit('testcollection', snapshot.id, {v: 0, create: {}}, snapshot, null, cb);
+    }, function(err) {
+      if (err) return done(err);
+
+      db.query('testcollection', query, null, null, function(err, results, extra) {
+        if (err) throw err;
+        expect(results).eql([snapshots[1]]);
+        done();
+      });
+    });
+  });
+
+  describe('top-level boolean operator', function() {
     var snapshots = [
       {type: 'json0', v: 1, data: {x: 1, y: 1}, id: "test1"},
       {type: 'json0', v: 1, data: {x: 1, y: 2}, id: "test2"},