Correctly handle pre-version for plugins checks

lib/configuration.js

@@ -5,6 +5,7 @@ var semver = require('semver');
 
 var pkg = require('../package.json');
 var i18n = require('./utils/i18n');
+var version = require('./version');
 
 var DEFAULT_CONFIG = require('./config_default');
 
@@ -139,7 +140,7 @@ Configuration.prototype.load = function() {
     })
     .then(function() {
         if (!that.book.isSubBook()) {
-            if (!semver.satisfies(pkg.version, that.options.gitbook)) {
+            if (!version.satisfies(that.options.gitbook)) {
                 throw new Error('GitBook version doesn\'t satisfy version required by the book: '+that.options.gitbook);
             }
             if (that.options.gitbook != '*' && !semver.satisfies(semver.inc(pkg.version, 'patch'), that.options.gitbook)) {

lib/plugin.js

@@ -1,6 +1,5 @@
 var _ = require('lodash');
 var Q = require('q');
-var semver = require('semver');
 var path = require('path');
 var url = require('url');
 var fs = require('./utils/fs');
@@ -9,7 +8,7 @@ var mergeDefaults = require('merge-defaults');
 var jsonschema = require('jsonschema');
 var jsonSchemaDefaults = require('json-schema-defaults');
 
-var pkg = require('../package.json');
+var version = require('./version');
 
 var PLUGIN_PREFIX = 'gitbook-plugin-';
 
@@ -145,7 +144,7 @@ Plugin.prototype.isValid = function() {
         this.packageInfos.name &&
         this.packageInfos.engines &&
         this.packageInfos.engines.gitbook &&
-        semver.satisfies(pkg.version, this.packageInfos.engines.gitbook)
+        version.satisfies(this.packageInfos.engines.gitbook)
     );
 
     // Valid hooks

lib/version.js

@@ -0,0 +1,19 @@
+var semver = require('semver');
+var pkg = require('../package.json');
+
+var VERSION = pkg.version;
+var VERSION_STABLE = VERSION.replace(/\-(\S+)/g, '');
+
+// Test if current current gitbook version satisfies a condition
+// We can't directly use samver.satisfies since it will break all plugins when gitbook version is a prerelease (beta, alpha)
+function satisfies(condition) {
+    // Test with real version
+    if (semver.satisfies(VERSION, condition)) return true;
+
+    // Test with future stable release
+    return semver.satisfies(VERSION_STABLE, condition);
+}
+
+module.exports = {
+    satisfies: satisfies
+};