Let deps :tree print a dependency tree

leiningen-core/src/leiningen/core/classpath.clj

@@ -76,6 +76,19 @@
 (defn add-auth [repositories]
   (map add-repo-auth repositories))
 
+(defn- get-dependencies
+  [dependencies-key {:keys [repositories native-path] :as project}
+   & {:keys [add-classpath?]}]
+  {:pre [(every? vector? (project dependencies-key))]}
+  ((if add-classpath?
+      pomegranate/add-dependencies
+      aether/resolve-dependencies)
+    :local-repo (:local-repo project)
+    :offline? (:offline project)
+    :repositories (add-auth repositories)
+    :coordinates (project dependencies-key)
+    :transfer-listener :stdout))
+
 (defn resolve-dependencies
   "Simply delegate regular dependencies to pomegranate. This will
   ensure they are downloaded into ~/.m2/repositories and that native
@@ -85,19 +98,18 @@
 
    Returns a set of the dependencies' files."
   [dependencies-key {:keys [repositories native-path] :as project}
-   & {:keys [add-classpath?]}]
+   & rest]
-  {:pre [(every? vector? (project dependencies-key))]}
   (doto (set (aether/dependency-files
-              ((if add-classpath?
+              (apply get-dependencies dependencies-key project rest)))
-                 pomegranate/add-dependencies
-                 aether/resolve-dependencies)
-               :local-repo (:local-repo project)
-               :offline? (:offline project)
-               :repositories (add-auth repositories)
-               :coordinates (project dependencies-key)
-               :transfer-listener :stdout)))
     (extract-native-deps native-path)))
 
+(defn dependency-hierarchy
+  "Returns a graph of the project's dependencies."
+  [dependencies-key project]
+  (aether/dependency-hierarchy
+   (project dependencies-key)
+   (get-dependencies dependencies-key project)))
+
 (defn- normalize-path [root path]
   (let [f (io/file path)]
     (.getAbsolutePath (if (.isAbsolute f) f (io/file root path)))))

leiningen-core/test/leiningen/core/test/classpath.clj

@@ -29,6 +29,17 @@
                          "commons-fileupload-1.2.1.jar"))}
          (resolve-dependencies :dependencies project))))
 
+(deftest test-dependency-hierarchy
+  (doseq [f (reverse (file-seq (io/file (:root project))))]
+    (when (.exists f) (io/delete-file f)))
+  (is (= '{[org.clojure/clojure "1.3.0"] nil
+          [ring/ring-core "1.0.0-RC1"
+           :exclusions [[commons-codec]]]
+          {[commons-fileupload "1.2.1"] nil
+           [commons-io "1.4"] nil
+           [javax.servlet/servlet-api "2.5"] nil}}
+         (dependency-hierarchy :dependencies project))))
+
 (def directories
   ["/tmp/lein-sample-project/test"
    "/tmp/lein-sample-project/src"

src/leiningen/deps.clj

@@ -1,10 +1,16 @@
 (ns leiningen.deps
   "Download all dependencies."
-  (:require [leiningen.core.classpath :as classpath]))
+  (:require [leiningen.core.classpath :as classpath]
+            [clojure.pprint :as pp]))
 
 (defn deps
   "Download all dependencies.
 
 You should never need to invoke this manually."
-  [project]
+  ([project]
-  (classpath/resolve-dependencies :dependencies project))
+     (deps project nil))
+  ([project tree]
+     (if (= tree ":tree")
+       (do (pp/pprint (classpath/dependency-hierarchy :dependencies project))
+           (flush))
+       (classpath/resolve-dependencies :dependencies project))))

test/leiningen/test/deps.clj

@@ -16,6 +16,33 @@
     (doseq [[n v] sample-deps]
       (is (.exists (m2-dir n v)) (str n " was not downloaded.")))))
 
+(deftest ^:online test-dependency-hierarchy
+  (let [sample-deps [["ring" "1.0.0"] ["rome" "0.9"] ["jdom" "1.0"]]]
+    (doseq [[n v] sample-deps]
+      (delete-file-recursively (m2-dir n v) :silently))
+    (is (= (with-out-str
+             (clojure.pprint/pprint
+              '{[org.clojure/clojure "1.1.0"] nil
+                [ring "1.0.0"]
+                {[ring/ring-core "1.0.0"]
+                 {[commons-codec "1.4"] nil
+                  [commons-fileupload "1.2.1"] nil
+                  [commons-io "1.4"] nil
+                  [javax.servlet/servlet-api "2.5"] nil}
+                 [ring/ring-devel "1.0.0"]
+                 {[clj-stacktrace "0.2.2"] nil
+                  [hiccup "0.3.7"] nil
+                  [ns-tracker "0.1.1"]
+                  {[org.clojure/tools.namespace "0.1.0"]
+                   {[org.clojure/java.classpath "0.1.0"] nil}}}
+                 [ring/ring-jetty-adapter "1.0.0"]
+                 {[org.mortbay.jetty/jetty-util "6.1.25"] nil
+                  [org.mortbay.jetty/jetty "6.1.25"]
+                  {[org.mortbay.jetty/servlet-api "2.5-20081211"] nil}}
+                 [ring/ring-servlet "1.0.0"] nil}
+                [rome "0.9"] {[jdom "1.0"] nil}}))
+           (with-out-str (deps sample-project ":tree"))))))
+
 (deftest ^:online test-snapshots-releases
   (let [pr (assoc sample-project :omit-default-repositories true
                   :repositories {"clojars" {:url "http://clojars.org/repo/"