Add terminating newlines to output files

src/rules_clojure/fs.clj

@@ -139,3 +139,8 @@
 
 (defn new-temp-file [dir prefix suffix]
   (Files/createTempFile (->path dir) prefix suffix (into-array FileAttribute [])))
+
+(defn spit-file [f content & opts]
+  (let [has-newline? (= \newline (last content))
+        content (if has-newline? content (str content \newline))]
+    (apply spit f (str content) opts)))

src/rules_clojure/gen_build.clj

@@ -729,7 +729,7 @@
     (-> dir
         (fs/->path "BUILD.bazel")
         fs/path->file
-        (spit content :encoding "UTF-8"))))
+        (fs/spit-file content :encoding "UTF-8"))))
 
 (s/fdef gen-source-paths- :args (s/cat :a (s/keys :req-un [::deps-edn-dir ::src-ns->label ::dep-ns->label ::jar->lib ::deps-repo-tag ::deps-bazel]) :paths (s/coll-of fs/path?)))
 (defn gen-source-paths-
@@ -808,7 +808,7 @@
   "generates the BUILD file for @deps//: with a single target containing all deps.edn-resolved dependencies"
   [{:keys [repository-dir deps-build-dir dep-ns->label jar->lib lib->jar lib->deps deps-repo-tag deps-bazel] :as args}]
   (println "writing to" (-> (fs/->path deps-build-dir "BUILD.bazel") fs/path->file))
-  (spit (-> (fs/->path deps-build-dir "BUILD.bazel") fs/path->file)
+  (fs/spit-file (-> (fs/->path deps-build-dir "BUILD.bazel") fs/path->file)
         (str/join "\n\n" (concat
                           [(emit-bazel (list 'package (kwargs {:default_visibility ["//visibility:public"]})))
                            (emit-bazel (list 'load "@rules_clojure//:rules.bzl" "clojure_library"))]
@@ -987,7 +987,7 @@
                (apply disj $ output-ns exclude-nses)
                (sort $))
         conditional-require? (re-matches #".*\.cljc$" output-filename)]
-    (spit (fs/path->file (fs/->path workspace-root output-filename))
+    (fs/spit-file (fs/path->file (fs/->path workspace-root output-filename))
           (str ";;; Generated by bazel, do not edit\n\n"
                (str "(ns " output-ns "\n")
                (str "  "

test/rules_clojure/BUILD

@@ -50,3 +50,7 @@ clojure_test(name="persistent-classloader-test",
 clojure_test(name="compile-test",
              deps=[":test-deps"],
              test_ns = "rules-clojure.compile-test")
+
+clojure_test(name="fs-test",
+             deps=[":test-deps"],
+             test_ns = "rules-clojure.fs-test")

test/rules_clojure/fs_test.clj

@@ -0,0 +1,20 @@
+(ns rules-clojure.fs-test
+  (:require [clojure.java.shell :as shell]
+            [clojure.string :as str]
+            [clojure.test :refer :all]
+            [rules-clojure.fs :as fs]))
+
+(defn count-lines [f]
+  (-> (shell/sh "wc" "-l" f)
+                 :out
+                 str/trim
+                 first
+                 str
+                 Long/parseLong))
+
+(deftest spit-file
+  (let [tmp-file "/tmp/spit-test.txt"]
+    (spit tmp-file "test with spit")
+    (is (= 0 (count-lines tmp-file)))
+    (fs/spit-file tmp-file "test with fs/spit-file")
+    (is (= 1 (count-lines tmp-file)))))