From 7929a2d973b5a81f79903c429010e9ad71e25a75 Mon Sep 17 00:00:00 2001
From: Pierre Colle <piercus@gmail.com>
Date: Mon, 29 Jan 2018 15:03:35 +0100
Subject: [PATCH 1/2] add auto resolver

---
 lib/container.js      |  1 +
 lib/resolvers/auto.js | 36 ++++++++++++++++++++++++++++++++++++
 2 files changed, 37 insertions(+)
 create mode 100644 lib/resolvers/auto.js

diff --git a/lib/container.js b/lib/container.js
index 392fd09..5c933d8 100644
--- a/lib/container.js
+++ b/lib/container.js
@@ -47,6 +47,7 @@ function Container() {
   this._resolvers = [];
   
   this.resolver(require('./resolvers/id')());
+  this.resolver(require('./resolvers/auto')());
 }
 
 // Inherit from `EventEmitter`.
diff --git a/lib/resolvers/auto.js b/lib/resolvers/auto.js
new file mode 100644
index 0000000..dd94f93
--- /dev/null
+++ b/lib/resolvers/auto.js
@@ -0,0 +1,36 @@
+/**
+ * Automatic interface resolver.
+ *
+ * Automatically resolves an interface to an object that implements that
+ * interface.  Automatic resolution reduces the amount of configuration that
+ * must be specified.
+ *
+ * For consistency and saftey in the development cycle, such resolution succeeds
+ * if and only if there is one object within the container that implements the
+ * interface.  If multiple objects implement the interface, automatic resolution
+ * would be ambiguous, and is therefore not performed.  In such cases, the exact
+ * object to resolve can be explicitly declared in configuration.
+ *
+ * @return {function}
+ * @protected
+ */
+module.exports = function(container) {
+  
+  return function(iface, pid) {
+    var specs = container.components()
+      , candidates = []
+      , spec, i, len;
+    for (i = 0, len = specs.length; i < len; ++i) {
+      spec = specs[i];
+      if (spec.implements.indexOf(iface) !== -1) {
+        candidates.push(spec.id);
+      }
+    }
+    
+    if (candidates.length == 1) {
+      return candidates[0];
+    } else if (candidates.length > 1) {
+      throw new Error('Multiple objects implement interface \"' + iface + '\" required by \"' + (pid || 'unknown') + '\". Configure one of: ' + candidates.join(', '));
+    }
+  };
+}

From ac7a0325e66d41780fa4e3becc7cf9e0a8d6528d Mon Sep 17 00:00:00 2001
From: Pierre Colle <piercus@gmail.com>
Date: Mon, 29 Jan 2018 15:32:38 +0100
Subject: [PATCH 2/2] add this to container

---
 lib/container.js | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/lib/container.js b/lib/container.js
index 5c933d8..8f2e345 100644
--- a/lib/container.js
+++ b/lib/container.js
@@ -47,7 +47,7 @@ function Container() {
   this._resolvers = [];
   
   this.resolver(require('./resolvers/id')());
-  this.resolver(require('./resolvers/auto')());
+  this.resolver(require('./resolvers/auto')(this));
 }
 
 // Inherit from `EventEmitter`.