Fix for #1840, Strip operations from results, forwards delete operations to SDKs (#1946)

* Adding a test demonstrating issue #1840.

* Fixes #1840

* Adds failing test with other use case

- That test fails on parse.com as well

* Bumps parse to 1.9.0

* exclude pg db

* Exclude pg on other test

* Adds clientSDK compatibility check for forward deletion

- Mark js1.9.0 as compatible

* Strips all operations from result

- fix for #1606

src/ClientSDK.js

@@ -0,0 +1,40 @@
+var semver = require('semver');
+
+function compatible(compatibleSDK) {
+  return function(clientSDK) {
+    if (typeof clientSDK === 'string') {
+      clientSDK = fromString(clientSDK);
+    }
+    // REST API, or custom SDK
+    if (!clientSDK) {
+      return true;
+    }
+    let clientVersion = clientSDK.version;
+    let compatiblityVersion = compatibleSDK[clientSDK.sdk];
+    return semver.satisfies(clientVersion, compatiblityVersion);
+  }
+}
+
+function supportsForwardDelete(clientSDK) {
+  return compatible({
+    js: '>=1.9.0'
+  })(clientSDK);
+}
+
+function fromString(version) {
+  let versionRE = /([-a-zA-Z]+)([0-9\.]+)/;
+  let match = version.toLowerCase().match(versionRE);
+  if (match && match.length === 3) {
+    return {
+      sdk: match[1],
+      version: match[2]
+    }
+  }
+  return undefined;
+}
+
+module.exports = {
+  compatible,
+  supportsForwardDelete,
+  fromString
+}