Support clj-reload workflow (#850)

Fixes #849

README.md

@@ -136,6 +136,7 @@ Let's also acknowledge some of the projects leveraged by cider-nrepl:
 * [clj-suitable][] - for ClojureScript code completion using runtime inspection
 * [tools.trace][] - for tracing
 * [tools.namespace][] - for namespace reloading
+* [clj-reload][] - for namespace reloading
 * [cljfmt][] - for code formatting
 
 ## License
@@ -149,6 +150,7 @@ Distributed under the Eclipse Public License, the same as Clojure.
 [clj-suitable]: https://github.com/clojure-emacs/clj-suitable
 [tools.trace]: https://github.com/clojure/tools.trace
 [tools.namespace]: https://github.com/clojure/tools.namespace
+[clj-reload]: https://github.com/tonsky/clj-reload
 [cljfmt]: https://github.com/weavejester/cljfmt
 [vim-replant]: https://github.com/SevereOverfl0w/vim-replant
 [vim-fireplace]: https://github.com/tpope/vim-fireplace

doc/modules/ROOT/pages/nrepl-api/ops.adoc

@@ -1783,3 +1783,54 @@ Returns::
 * `:status` done
 * `:cider/log-update-consumer` The consumer that was updated.
 
+
+
+=== `cider.clj-reload/reload`
+
+Reloads all changed files in dependency order,
+using the io.github.tonsky/clj-reload library. It is bundled with cider-nrepl.
+If that dependency is already in present your project and clj-reload.core/init has been invoked beforehand,
+those configured directories will be honored.
+
+Required parameters::
+{blank}
+
+Optional parameters::
+{blank}
+
+Returns::
+* `:error` A sequence of all causes of the thrown exception when ``status`` is ``:error``.
+* `:progress` Description of current namespace being unloaded/loaded.
+* `:status` ``:ok`` if reloading was successful; otherwise ``:error``.
+
+
+
+=== `cider.clj-reload/reload-all`
+
+Reloads all files in dependency order.
+
+Required parameters::
+{blank}
+
+Optional parameters::
+{blank}
+
+Returns::
+* `:error` A sequence of all causes of the thrown exception when ``status`` is ``:error``.
+* `:reloading` Description of current namespace being unloaded/loaded.
+* `:status` ``:ok`` if reloading was successful; otherwise ``:error``.
+
+
+
+=== `cider.clj-reload/reload-clear`
+
+Clears the state of clj-reload. This can help recover from a failed load or a circular dependency error.
+
+Required parameters::
+{blank}
+
+Optional parameters::
+{blank}
+
+Returns::
+{blank}

doc/modules/ROOT/pages/usage.adoc

@@ -47,6 +47,7 @@ under `:repl-options`.
                   cider.nrepl/wrap-spec
                   cider.nrepl/wrap-profile
                   cider.nrepl/wrap-refresh
+                  cider.nrepl/wrap-reload
                   cider.nrepl/wrap-resource
                   cider.nrepl/wrap-stacktrace
                   cider.nrepl/wrap-test
@@ -161,6 +162,7 @@ That's how CIDER's nREPL handler is created:
     cider.nrepl/wrap-slurp
     cider.nrepl/wrap-profile
     cider.nrepl/wrap-refresh
+    cider.nrepl/wrap-reload
     cider.nrepl/wrap-resource
     cider.nrepl/wrap-spec
     cider.nrepl/wrap-stacktrace

project.clj

@@ -19,6 +19,7 @@
                  ~(with-meta '[org.clojure/tools.namespace "1.3.0"]
                     ;; :cognitest uses tools.namespace, so we cannot inline it while running tests.
                     {:inline-dep (not= "true" (System/getenv "SKIP_INLINING_TEST_DEPS"))})
+                 ^:inline-dep [io.github.tonsky/clj-reload "0.4.0"]
                  ^:inline-dep [org.clojure/tools.trace "0.7.11"]
                  ^:inline-dep [org.clojure/tools.reader "1.3.6"]
                  [mx.cider/logjam "0.3.0"]]
@@ -157,6 +158,7 @@
                                                               cider.nrepl/wrap-out
                                                               cider.nrepl/wrap-profile
                                                               cider.nrepl/wrap-refresh
+                                                              cider.nrepl/wrap-reload
                                                               cider.nrepl/wrap-resource
                                                               cider.nrepl/wrap-slurp
                                                               cider.nrepl/wrap-spec

src/cider/nrepl.clj

@@ -635,6 +635,25 @@ if applicable, and re-render the updated value."
              "refresh-clear"
              {:doc "Clears the state of the refresh middleware. This can help recover from a failed load or a circular dependency error."}}})
 
+(def-wrapper wrap-reload cider.nrepl.middleware.reload/handle-reload
+  {:doc "Reload middleware."
+   :requires #{"clone" #'wrap-print}
+   :handles {"cider.clj-reload/reload"
+             {:doc "Reloads all changed files in dependency order,
+using the io.github.tonsky/clj-reload library. It is bundled with cider-nrepl.
+If that dependency is already in present your project and clj-reload.core/init has been invoked beforehand,
+those configured directories will be honored."
+              :returns {"progress" "Description of current namespace being unloaded/loaded."
+                        "status" "`:ok` if reloading was successful; otherwise `:error`."
+                        "error" "A sequence of all causes of the thrown exception when `status` is `:error`."}}
+             "cider.clj-reload/reload-all"
+             {:doc "Reloads all files in dependency order."
+              :returns {"reloading" "Description of current namespace being unloaded/loaded."
+                        "status" "`:ok` if reloading was successful; otherwise `:error`."
+                        "error" "A sequence of all causes of the thrown exception when `status` is `:error`."}}
+             "cider.clj-reload/reload-clear"
+             {:doc "Clears the state of clj-reload. This can help recover from a failed load or a circular dependency error."}}})
+
 (def-wrapper wrap-resource cider.nrepl.middleware.resource/handle-resource
   {:doc "Middleware that provides the path to resource."
    :handles {"resource"

src/cider/nrepl/middleware.clj

@@ -23,6 +23,7 @@
     cider.nrepl/wrap-slurp
     cider.nrepl/wrap-profile
     cider.nrepl/wrap-refresh
+    cider.nrepl/wrap-reload
     cider.nrepl/wrap-resource
     cider.nrepl/wrap-spec
     cider.nrepl/wrap-stacktrace

src/cider/nrepl/middleware/reload.clj

@@ -0,0 +1,67 @@
+(ns cider.nrepl.middleware.reload
+  "Reload changed namespaces.
+  Alternative to cider.nrepl.middleware.refresh, using clj-reload instead
+  of tools.namespace."
+  (:require
+   [clj-reload.core :as reload]
+   [clojure.main :refer [repl-caught]]
+   [clojure.string :as str]
+   [haystack.analyzer :as analyzer]
+   [nrepl.middleware.interruptible-eval :refer [*msg*]]
+   [nrepl.middleware.print :as print]
+   [nrepl.misc :refer [response-for]]
+   [nrepl.transport :as transport]
+   [orchard.misc :as misc]))
+
+(defn- user-reload
+  "Resolve clj-reload.core/<sym> from the user project or return fallback."
+  [sym fallback]
+  (or (some-> (symbol "clj-reload.core" (str sym)) ;; Don't use mrandorsenized version
+              resolve)
+      fallback))
+
+(defn- init
+  "Initialize clj-reload with dirs.
+  Only used for test, but necessary because of mranderson."
+  [dirs]
+  (reload/init {:dirs dirs}))
+
+(defn respond
+  [{:keys [transport] :as msg} response]
+  (transport/send transport (response-for msg response)))
+
+(defn operation
+  [msg]
+  (let [opts   {:log-fn (fn [& args]
+                          (respond msg {:progress (str/join " " args)}))}
+        reload (user-reload 'reload reload/reload)
+        unload (user-reload 'unload reload/unload)]
+    (cond
+      (:all msg)   (reload (assoc opts :all true))
+      (:clear msg) (unload opts)
+      :else        (reload opts))))
+
+(defn- reload-reply
+  [{:keys [::print/print-fn transport session id] :as msg}]
+  (let [{:keys [exec]} (meta session)]
+    (exec id
+          (fn []
+            (try
+              (operation msg)
+              (respond msg {:status :ok})
+              (catch Throwable error
+                (respond msg {:status :error
+                              ;; TODO assoc :file, :line info if available
+                              :error  (analyzer/analyze error print-fn)})
+                (binding [*msg* msg
+                          *err* (print/replying-PrintWriter :err msg {})]
+                  (repl-caught error)))))
+
+          (fn [] (respond msg {:status :done})))))
+
+(defn handle-reload [handler msg]
+  (case (:op msg)
+    "cider.clj-reload/reload" (reload-reply msg)
+    "cider.clj-reload/reload-all" (reload-reply (assoc msg :all true))
+    "cider.clj-reload/reload-clear" (reload-reply (assoc msg :clear true))
+    (handler msg)))

test/clj/cider/nrepl/middleware/reload_test.clj

@@ -0,0 +1,46 @@
+(ns cider.nrepl.middleware.reload-test
+  (:require
+   [cider.nrepl.middleware.reload :as rl]
+   [cider.nrepl.test-session :as session]
+   [clojure.test :refer :all]))
+
+(use-fixtures :each session/session-fixture)
+
+(def ^:private dirs-to-reload
+  ;; Limit the scope of what we reload, because (for example) reloading the
+  ;; cider.nrepl.middleware.test-session ns causes *session* in that ns to be
+  ;; unloaded, which breaks session-fixture, and hence all of the below tests.
+  ["test/clj/cider/nrepl/middleware/util"])
+
+;; Calling init from reload ns to work around mrandersonized version
+;; See cider.nrepl.middleware.refresh-test for another test that suffers from this.
+(#'rl/init dirs-to-reload)
+
+(deftest user-reload
+  (testing "returns fallback if clojure.tools.namespace isn't loaded"
+    (with-redefs [resolve (constantly nil)]
+      (is (= :foo (#'rl/user-reload 'reload :foo))))))
+
+(deftest reload-op-test
+  (testing "reload op works"
+    (let [response (session/message {:op "cider.clj-reload/reload"})]
+      ;; There is nothing to reload since the files did not change,
+      ;; but the message does come from clj-reload.core/reload.
+      ;; It's two separate messages, but in (:progress response) they are
+      ;; concatenated.
+      (is (= "Nothing to unloadNothing to reload" (:progress response)))
+      (is (= #{"done" "ok"} (:status response))))))
+
+(deftest reload-all-op-test
+  (testing "reload-all op works"
+    (let [response (session/message {:op "cider.clj-reload/reload-all"})]
+      (is (seq (:progress response)))
+      (is (= #{"done" "ok"} (:status response))))))
+
+(deftest reload-clear-op-test
+  (testing "reload-all op works"
+    (let [response (session/message {:op "cider.clj-reload/reload-clear"})]
+      (is (seq (:progress response)))
+      (is (= "Nothing to unload" (:progress response)))
+      (is (= #{"done" "ok"} (:status response))))))
+