Support patched MSSQL lib (#2861)

* PATCH Support patched MSSQL lib

* Add code coverage ignores to mssql monkey-patching

* Fix compatibility description

package.json

@@ -53,7 +53,7 @@
     "lint-staged": "^8.0.4",
     "mocha": "^5.2.0",
     "mock-fs": "^4.7.0",
-    "mssql": "4.1.0",
+    "mssql": "^5.0.0-alpha.1",
     "mysql": "^2.16.0",
     "mysql2": "^1.6.4",
     "nyc": "^13.0.1",

src/dialects/mssql/index.js

@@ -61,25 +61,31 @@ assign(Client_MSSQL.prototype, {
 
     // TODO: remove mssql implementation all together and use tedious directly
 
+    /* istanbul ignore next */
     const mssqlVersion = require('mssql/package.json').version;
-    if (mssqlVersion !== '4.1.0') {
-      throw new Error(
-        'This knex version does not support any other mssql version except 4.1.0 ' +
-          '(knex patches bug in its implementation)'
-      );
+    /* istanbul ignore next */
+    if (mssqlVersion === '4.1.0') {
+      mssqlTedious.ConnectionPool.prototype.release = release;
+      mssqlTedious.ConnectionPool.prototype._poolCreate = _poolCreate;
+    } else {
+      const [major] = mssqlVersion.split('.');
+      // if version is not ^5.0.0
+      if (major < 5) {
+        throw new Error(
+          'This knex version only supports mssql driver versions 4.1.0 and 5.0.0+'
+        );
+      }
     }
 
-    mssqlTedious.ConnectionPool.prototype.release = release;
-    mssqlTedious.ConnectionPool.prototype._poolCreate = _poolCreate;
-
+    /* istanbul ignore next */
     // in some rare situations release is called when stream is interrupted, but
     // after pool is already destroyed
     function release(connection) {
       if (this.pool) {
         this.pool.release(connection);
       }
     }
-
+    /* istanbul ignore next */
     function _poolCreate() {
       // implementation is copy-pasted from https://github.com/tediousjs/node-mssql/pull/614
       return new base.Promise((resolve, reject) => {