Fix and test regression in defonce handling

nextjournal · Jan 26, 2022 · 571bf11 · 571bf11
1 parent 5aa2a55
commit 571bf11
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Showing 2 changed files with 10 additions and 2 deletions.
diff --git a/src/nextjournal/clerk.clj b/src/nextjournal/clerk.clj
@@ -110,8 +110,11 @@
       (cache! digest-file var-value))
     (let [blob-id (cond no-cache? (view/->hash-str var-value)
                         (fn? var-value) nil
-                        :else hash)]
-      (wrapped-with-metadata (cond-> result introduced-var var-from-def) visibility blob-id))))
+                        :else hash)
+          result (if introduced-var
+                   (var-from-def introduced-var)
+                   result)]
+      (wrapped-with-metadata result visibility blob-id))))
 
 
 (defn read+eval-cached [results-last-run ->hash doc-visibility codeblock]

diff --git a/test/nextjournal/clerk_test.clj b/test/nextjournal/clerk_test.clj
@@ -71,6 +71,11 @@
     (is (not= (clerk/eval-string "(ns ^:nextjournal.clerk/no-cache my-random-test-ns) (java.util.UUID/randomUUID)")
               (clerk/eval-string "(ns ^:nextjournal.clerk/no-cache my-random-test-ns) (java.util.UUID/randomUUID)"))))
 
+  (testing "defonce returns correct result on subsequent evals (when defonce would eval to nil)"
+    (clerk/eval-string "(ns ^:nextjournal.clerk/no-cache my-defonce-test-ns) (defonce state (atom {}))")
+    (is (match? {:blocks [map? {:result {:nextjournal/value {::clerk/var-from-def var?}}}]}
+                (clerk/eval-string "(ns ^:nextjournal.clerk/no-cache my-defonce-test-ns) (defonce state (atom {}))"))))
+
   (testing "assigning viewers from form meta"
     (is (match? {:blocks [{:result {:nextjournal/viewer #'nextjournal.clerk/table}}]}
                 (clerk/eval-string "^{:nextjournal.clerk/viewer nextjournal.clerk/table} (def markup [:h1 \"hi\"])")))