CLJS-2232: Self-host: Add support for string-based requires

Author: anmonteiro

src/main/cljs/cljs/js.cljs

@@ -575,6 +575,15 @@
          (check-uses-and-load-macros {:value nil} ast)))
      (cb {:value ast}))))
 
+(defn- node-side-effects
+  [bound-vars sb deps ns-name]
+  (doseq [dep deps]
+    (.append sb
+      (with-out-str
+        (comp/emitln (munge ns-name) "."
+          (ana/munge-node-lib dep)
+          " = require('" dep "');")))))
+
 (defn- analyze-str* [bound-vars source name opts cb]
   (let [rdr        (rt/indexing-push-back-reader source 1 name)
         eof        (js-obj)
@@ -716,14 +725,22 @@
                          (str "Could not eval " form) cause))))]
         (if (:error res)
           (cb res)
-          (let [ast (:value res)]
+          (let [ast (:value res)
+                [node-deps ast] (if (keyword-identical? (:target opts) :nodejs)
+                                  (let [{node-libs true libs-to-load false} (group-by ana/node-module-dep? (:deps ast))]
+                                    [node-libs (assoc ast :deps libs-to-load)])
+                                  [nil ast])]
             (if (#{:ns :ns*} (:op ast))
               (ns-side-effects true bound-vars aenv ast opts
                 (fn [res]
                   (if (:error res)
                     (cb res)
-                    (let [src (str "goog.provide(\"" (comp/munge (:name ast)) "\")")]
-                      (cb {:value (*eval-fn* {:source src})})))))
+                    (let [sb (StringBuffer.)]
+                      (.append sb
+                        (with-out-str (comp/emitln (str "goog.provide(\"" (comp/munge (:name ast)) "\");"))))
+                      (when-not (nil? node-deps)
+                        (node-side-effects bound-vars sb node-deps (:name ast)))
+                      (cb {:value (*eval-fn* {:source (.toString sb)})})))))
               (let [src (with-out-str (comp/emit ast))]
                 (cb {:value (*eval-fn* {:source src})})))))))))
 
@@ -822,14 +839,21 @@
                                     (str "Could not compile " name) cause))))]
                    (if (:error res)
                      (cb res)
-                     (let [ast (:value res)]
+                     (let [ast (:value res)
+                           [node-deps ast] (if (keyword-identical? (:target opts) :nodejs)
+                                             (let [{node-libs true libs-to-load false} (group-by ana/node-module-dep? (:deps ast))]
+                                               [node-libs (assoc ast :deps libs-to-load)])
+                                             [nil ast])]
                        (.append sb (with-out-str (comp/emit ast)))
                        (if (#{:ns :ns*} (:op ast))
                          (ns-side-effects bound-vars aenv ast opts
                            (fn [res]
                              (if (:error res)
                                (cb res)
-                               (compile-loop (:name ast)))))
+                               (do
+                                 (when-not (nil? node-deps)
+                                   (node-side-effects bound-vars sb node-deps (:name ast)))
+                                 (compile-loop (:name ast))))))
                          (recur ns)))))
                  (do
                    (when (:source-map opts)
@@ -944,7 +968,11 @@
                    (if (:error res)
                      (cb res)
                      (let [ast (:value res)
-                           ns' ana/*cljs-ns*]
+                           ns' ana/*cljs-ns*
+                           [node-deps ast] (if (keyword-identical? (:target opts) :nodejs)
+                                             (let [{node-libs true libs-to-load false} (group-by ana/node-module-dep? (:deps ast))]
+                                               [node-libs (assoc ast :deps libs-to-load)])
+                                             [nil ast])]
                       (if (#{:ns :ns*} (:op ast))
                         (do
                           (.append sb
@@ -953,7 +981,10 @@
                             (fn [res]
                               (if (:error res)
                                 (cb res)
-                                (compile-loop ns')))))
+                                (do
+                                  (when-not (nil? node-deps)
+                                    (node-side-effects bound-vars sb node-deps (:name ast)))
+                                  (compile-loop ns'))))))
                         (do
                           (.append sb (with-out-str (comp/emit ast)))
                           (recur ns'))))))

src/main/clojure/cljs/analyzer.cljc

@@ -744,10 +744,16 @@
     (str module)))
 
 (defn node-module-dep?
+  #?(:cljs {:tag boolean})
   [module]
-  (contains?
-    (get-in @env/*compiler* [:node-module-index])
-    (str module)))
+  #?(:clj (contains?
+            (get-in @env/*compiler* [:node-module-index])
+            (str module))
+     :cljs (try
+             (and (= *target* "nodejs")
+                  (boolean (js/require.resolve (str module))))
+             (catch :default _
+               false))))
 
 (defn dep-has-global-exports?
   [module]

src/test/self/self_host/test.cljs

@@ -916,6 +916,66 @@
           (is (every? symbol? (keys (get-in @st [:cljs.analyzer/namespaces]))))
           (inc! l))))))
 
+(deftest test-string-requires-cljs-2232
+  (async done
+    (let [st (cljs/empty-state)
+          l (latch 4 done)]
+      (cljs/compile-str
+        (atom @st)
+        "(ns foo.core (:require [path]))"
+        nil
+        {:context :expr
+         :target :nodejs
+         :eval node-eval}
+        (fn [{:keys [error value] :as m}]
+          (is (nil? error))
+          (is (some? (re-find #"foo\.core\.node\$module\$path = require\('path'\);" value)))
+          (inc! l)))
+      (cljs/eval-str
+        (atom @st)
+        "(ns foo.core (:require [path])) (path/basename \"/foo/bar\")"
+        nil
+        {:context :expr
+         :target :nodejs
+         :eval node-eval}
+        (fn [{:keys [error value] :as m}]
+          (is (nil? error))
+          (is (= value "bar"))
+          (inc! l)))
+      (cljs/analyze-str
+        (atom @st)
+        "(ns foo.core (:require [path]))"
+        nil
+        {:context :expr
+         :target :nodejs
+         :load (fn [_ cb]
+                 (cb {:lang   :js
+                      :source ""}))}
+        (fn [{:keys [error value] :as m}]
+          (is (nil? error))
+          (is (= (:deps value) '[path]))
+          (inc! l)))
+      (let [st (cljs/empty-state)]
+        (cljs/eval
+          st
+          '(ns foo.core (:require [path]))
+          {:context :expr
+           :target :nodejs
+           :eval node-eval}
+          (fn [{:keys [error value] :as m}]
+            (is (nil? error))
+            (cljs/eval
+              st
+              '(path/basename "/foo/bar")
+              {:context :expr
+               :ns 'foo.core
+               :target :nodejs
+               :eval node-eval}
+              (fn [{:keys [error value]}]
+                (is (nil? error))
+                (is (= value "bar"))
+                (inc! l)))))))))
+
 (defn -main [& args]
   (run-tests))