Improve ClojureScript->JavaScript roundtripping, and flesh out example Node test.

src/common/datomish/js.cljs

@@ -12,6 +12,7 @@
      [cljs.reader]
      [cljs-promises.core :refer [promise]]
      [datomish.cljify :refer [cljify]]
+     [datomish.api :as d]
      [datomish.db :as db]
      [datomish.db-factory :as db-factory]
      [datomish.pair-chan]
@@ -24,14 +25,13 @@
 
 ;; Public API.
 
-(defn ^:export db [conn]
-  (transact/db conn))
+(def ^:export db d/db)
 
 (defn ^:export q [db find options]
   (let [find (cljs.reader/read-string find)
         opts (cljify options)]
     (take-pair-as-promise!
-      (db/<?q db find opts)
+      (d/<q db find opts)
       clj->js)))
 
 (defn ^:export ensure-schema [conn simple-schema]
@@ -39,7 +39,7 @@
         datoms (simple-schema/simple-schema->schema simple-schema)]
     (println "Transacting schema datoms" (pr-str datoms))
     (take-pair-as-promise!
-      (transact/<transact!
+      (d/<transact!
         conn
         datoms)
       clj->js)))
@@ -52,9 +52,8 @@
   ;; Expects a JS array as input.
   (try
     (let [tx-data (js->tx-data tx-data)]
-      (println "Transacting:" (pr-str tx-data))
       (go-promise clj->js
-        (let [tx-result (<? (transact/<transact! conn tx-data))]
+        (let [tx-result (<? (d/<transact! conn tx-data))]
           (select-keys tx-result
                        [:tempids
                         :added-idents
@@ -73,10 +72,20 @@
         ;; We pickle the connection as a thunk here so it roundtrips through JS
         ;; without incident.
         {:conn (fn [] c)
-         :roundtrip (fn [x] (clj->js (cljify x)))
-         :db (fn [] (transact/db c))
+         :db (fn [] (d/db c))
+         :path path
+
+         ;; Primary API.
          :ensureSchema (fn [simple-schema] (ensure-schema c simple-schema))
          :transact (fn [tx-data] (transact c tx-data))
+         :q (fn [find opts] (q (d/db c) find opts))
          :close (fn [] (db/close-db db))
+
+         ;; Some helpers for testing the bridge.
+         :equal =
+         :idx (fn [tempid] (:idx tempid))
+         :cljify cljify
+         :roundtrip (fn [x] (clj->js (cljify x)))
+
          :toString (fn [] (str "#<DB " path ">"))
-         :path path}))))
+         }))))

src/node/datomish/cljify.cljs

@@ -1,7 +1,30 @@
 (ns datomish.cljify)
 
 (defn cljify
-  "In node, equivalent to `(js->clj o :keywordize-keys true).
-  See <http://dev.clojure.org/jira/browse/CLJS-439?focusedCommentId=43909>."
-  [o]
-  (js->clj o :keywordize-keys true))
+  "In node, equivalent to `(js->clj o :keywordize-keys true),
+  but successfully passes Clojure Records through. This allows JS API
+  callers to round-trip values they receive from ClojureScript APIs."
+  [x]
+  ;; This implementation is almost identical to js->clj, but it allows
+  ;; us to hook into the recursion into sequences and objects, and it
+  ;; passes through records.
+  (if (record? x)
+    x
+    (cond
+      (satisfies? IEncodeClojure x)
+      (-js->clj x (apply array-map {:keywordize-keys true}))
+
+      (seq? x)
+      (doall (map cljify x))
+
+      (coll? x)
+      (into (empty x) (map cljify x))
+
+      (array? x)
+      (vec (map cljify x))
+
+      (identical? (type x) js/Object)
+      (into {} (for [k (js-keys x)]
+                 [(keyword k) (cljify (aget x k))]))
+
+      :else x)))

test/js/tests.js

@@ -15,29 +15,63 @@ var schema = {
     {"name":         "page/title",
      "type":         "string",
      "cardinality":  "one",
-     "doc":          "A page's title."},
-    {"name":         "page/starred",
-     "type":         "boolean",
-     "cardinality":  "one",
-     "doc":          "Whether the page is starred."},
-    {"name":         "page/visit",
-     "type":         "ref",
-     "cardinality":  "many",
-     "doc":          "A visit to the page."}
+     "doc":          "A page's title."}
   ]
 };
 
 async function testOpen() {
+  // Open a database.
   let db = await datomish.open("/tmp/testing.db");
+
+  // Make sure we have our current schema.
   await db.ensureSchema(schema);
-  let txResult = await db.transact([{"db/id": 55,
-                                     "page/url": "http://foo.com/bar",
-                                     "page/starred": true}]);
+
+  // Add some data. Note that we use a temporary ID (the real ID
+  // will be assigned by Datomish).
+  let txResult = await db.transact([
+    {"db/id": datomish.tempid(),
+     "page/url": "https://mozilla.org/",
+     "page/title": "Mozilla"}
+  ]);
+
   console.log("Transaction returned " + JSON.stringify(txResult));
   console.log("Transaction instant: " + txResult.txInstant);
-  let results = await datomish.q(db.db(), "[:find ?url :in $ :where [?e :page/url ?url]]")
+
+  // A simple query.
+  let results = await db.q("[:find ?url :in $ :where [?e :page/url ?url]]");
   results = results.map(r => r[0]);
+
   console.log("Query results: " + JSON.stringify(results));
+
+  // Let's extend our schema. In the real world this would typically happen
+  // across releases.
+  schema.attributes.push({"name":        "page/visitedAt",
+                          "type":        "instant",
+                          "cardinality": "many",
+                          "doc":         "A visit to the page."});
+  await db.ensureSchema(schema);
+
+  // Now we can make assertions with the new vocabulary about existing
+  // entities.
+  // Note that we simply let Datomish find which page we're talking about by
+  // URL -- the URL is a unique property -- so we just use a tempid again.
+  await db.transact([
+    {"db/id": datomish.tempid(),
+     "page/url": "https://mozilla.org/",
+     "page/visitedAt": (new Date())}
+  ]);
+
+  // When did we most recently visit this page?
+  let date = (await db.q(
+    `[:find (max ?date)
+      :in $ ?url
+      :where
+      [?page :page/url ?url]
+      [?page :page/visitedAt ?date]]`,
+    {"inputs": {"url": "https://mozilla.org/"}}))[0][0];
+  console.log("Most recent visit: " + date);
+
+  // Close: we're done!
   await db.close();
 }