Fix NPE in builder/build-static-app! when there's nothing to build, c…

…loses #339
nextjournal · Dec 15, 2022 · 43c02b1 · 43c02b1
1 parent eb62d4c
commit 43c02b1
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Showing 2 changed files with 13 additions and 5 deletions.
diff --git a/src/nextjournal/clerk/builder.clj b/src/nextjournal/clerk/builder.clj
@@ -168,14 +168,16 @@
           :bundle? false
           :browse? false
           :report-fn (if @webserver/!server build-ui-reporter stdout-reporter)}
-         (let [opts' (cond-> opts
-                       index (assoc :index (str index)))
-               expanded-paths (when expand-paths? (expand-paths opts'))]
+         (let [opts+index (cond-> opts
+                            index (assoc :index (str index)))
+               {:as opts' :keys [expanded-paths]} (cond-> opts+index
+                                                    expand-paths? (merge (try {:expanded-paths (expand-paths opts+index)}
+                                                                              (catch Exception e
+                                                                                {:error e}))))]
            (-> opts'
                (update :resource->url #(merge {} %2 %1) @config/!resource->url)
-               (cond->
+               (cond-> #_opts'
                  expand-paths? (dissoc :expand-paths?)
-                 expanded-paths (assoc :expanded-paths expanded-paths)
                  (and (not index) (= 1 (count expanded-paths))) (assoc :index (first expanded-paths)))))))
 
 #_(process-build-opts {:index 'book.clj :expand-paths? true})

diff --git a/test/nextjournal/clerk/builder_test.clj b/test/nextjournal/clerk/builder_test.clj
@@ -50,12 +50,18 @@
                           (builder/expand-paths {:paths-fn 'clojure.core/non-existant-var})))
     (is (thrown-with-msg? ExceptionInfo #"must be a qualified symbol pointing at an existing var"
                           (builder/expand-paths {:paths-fn "hi"})))
+    (is (thrown-with-msg? ExceptionInfo #"nothing to build"
+                          (builder/expand-paths {:paths []})))
     (is (thrown-with-msg? ExceptionInfo #"An error occured invoking"
                           (builder/expand-paths {:paths-fn 'clojure.core/inc})))
     (is (thrown-with-msg? ExceptionInfo #"`:paths-fn` must compute sequential value"
                           (builder/expand-paths {:paths-fn 'clojure.core/+})))
     (is (thrown? ExceptionInfo (builder/expand-paths {:index ["book.clj"]})))))
 
+(deftest build-static-app!
+  (testing "error when paths are empty (issue #339)"
+    (is (thrown-with-msg? ExceptionInfo #"nothing to build" (builder/build-static-app! {:paths []})))))
+
 (deftest process-build-opts
   (testing "assigns index when only one path is given"
     (is (= (str (fs/file "notebooks" "rule_30.clj"))