Make native bindings an optional install

Makefile

@@ -7,7 +7,7 @@ params := $(connectionString)
 node-command := xargs -n 1 -I file node file $(params)
 
 .PHONY : test test-connection test-integration bench test-native \
-	build/default/binding.node jshint upgrade-pg publish
+	build/default/binding.node jshint upgrade-pg publish test-missing-native
 
 all:
 	npm install
@@ -21,7 +21,7 @@ help:
 
 test: test-unit
 
-test-all: jshint test-unit test-integration test-native test-binary
+test-all: jshint test-missing-native test-unit test-integration test-native test-binary
 
 test-travis: test-all upgrade-pg
 	#@make test-all connectionString=postgres://postgres@localhost:5433/postgres
@@ -44,7 +44,18 @@ test-connection-binary:
 	@echo "***Testing binary connection***"
 	@node script/test-connection.js $(params) binary
 
-test-native:
+test-missing-native:
+	@echo "***Testing optional native install***"
+	@rm -rf node_modules/pg-native
+	@node test/native/missing-native.js
+	@npm install pg-native@1.4.0
+	@node test/native/missing-native.js
+	@rm -rf node_modules/pg-native
+
+node_modules/pg-native/index.js:
+	@npm i pg-native
+
+test-native: node_modules/pg-native/index.js
 	@echo "***Testing native bindings***"
 	@find test/native -name "*-tests.js" | $(node-command)
 	@find test/integration -name "*-tests.js" | $(node-command) native

lib/index.js

@@ -67,16 +67,15 @@ PG.prototype.cancel = function(config, client, query) {
   cancellingClient.cancel(client, query);
 };
 
-var forceNative = Object.prototype.hasOwnProperty.call(process.env, 'NODE_PG_FORCE_NATIVE');
-if (forceNative) {
-  module.exports = new PG(require(__dirname + '/native'));
+if(typeof process.env.NODE_PG_FORCE_NATIVE != 'undefined') {
+  module.exports = new PG(require('./native'));
 } else {
   module.exports = new PG(Client);
 
   //lazy require native module...the native module may not have installed
   module.exports.__defineGetter__("native", function() {
     delete module.exports.native;
-    module.exports.native = new PG(require(__dirname + '/native'));
+    module.exports.native = new PG(require('./native'));
     return module.exports.native;
   });
 }

lib/native/index.js

@@ -1,8 +1,13 @@
 var Native = require('pg-native');
+var semver = require('semver');
+var pkg = require('../../package.json');
+var assert = require('assert');
 var EventEmitter = require('events').EventEmitter;
 var util = require('util');
 var ConnectionParameters = require(__dirname + '/../connection-parameters');
 
+assert(semver.gte(Native.version, pkg.minNativeVersion));
+
 var NativeQuery = require('./query');
 
 var Client = module.exports = function(config) {

lib/native/require.js

@@ -0,0 +1,4 @@
+
+var pgNative = require('pg-native');
+assert(semver.gte(pgNative.version, pkg.minNativeVersion));
+module.exports = require('./index');

package.json

@@ -23,7 +23,6 @@
     "nan": "1.3.0",
     "packet-reader": "0.2.0",
     "pg-connection-string": "0.1.3",
-    "pg-native": "1.4.3",
     "pg-types": "1.6.0",
     "pgpass": "0.0.3"
   },
@@ -32,6 +31,7 @@
     "jshint": "2.5.2",
     "semver": "~3.0.1"
   },
+  "minNativeVersion": "1.5.0",
   "scripts": {
     "changelog": "npm i github-changes && ./node_modules/.bin/github-changes -o brianc -r node-postgres -d pulls -a -v",
     "test": "make test-travis connectionString=postgres://postgres@localhost:5432/postgres"

test/native/missing-native.js

@@ -0,0 +1,8 @@
+//this test assumes it has been run from the Makefile
+//and that node_modules/pg-native has been deleted
+
+var assert = require('assert');
+
+assert.throws(function() {
+  require('../../lib').native;
+});