WIP integer to boolean coercion for SQLite; doesn't work.

src/metabase/driver/sql/query_processor.clj

@@ -223,6 +223,9 @@
       (ex-info (str "Cannot convert " (pr-str value) " to float.")
                {:value value}))))
 
+(defn- integer->boolean [expr]
+  (h2x/cast :boolean expr))
+
 (defmulti date-dbtype
   "Return the name of the date type we convert to in this database."
   {:added "0.55.0" :arglists '([driver])}
@@ -802,7 +805,7 @@
       (throw (Exception. (tru "No magnitude known for {0}" coercion-type)))))
 
 (defn cast-field-if-needed
-  "Wrap a `field-identifier` in appropriate HoneySQL expressions if it refers to a UNIX timestamp Field."
+  "Wrap a `field-identifier` in appropriate HoneySQL expressions if it needs casting."
   [driver {:keys [base-type coercion-strategy], :as field} honeysql-form]
   (if (some #(str/includes? (name %) "_") (keys field))
     (do
@@ -817,6 +820,9 @@
                                          (semantic-type->unix-timestamp-unit coercion-strategy)
                                          honeysql-form)
 
+               (and (isa? base-type :type/Number) (isa? coercion-strategy :Coercion/Integer->Boolean))
+               (integer->boolean honeysql-form)
+
                (and (= base-type :type/Text) (isa? coercion-strategy :Coercion/String->Temporal))
                (cast-temporal-string driver coercion-strategy honeysql-form)
 

src/metabase/types/core.cljc

@@ -365,6 +365,8 @@
 (derive :Coercion/UNIXMicroSeconds->DateTime :Coercion/UNIXTime->Temporal)
 (derive :Coercion/UNIXNanoSeconds->DateTime :Coercion/UNIXTime->Temporal)
 
+(derive :Coercion/Integer->Boolean :Coercion/*)
+
 (derive :Coercion/Temporal->Temporal :Coercion/*)
 (derive :Coercion/DateTime->Date :Coercion/Temporal->Temporal)
 
@@ -482,6 +484,8 @@
 (coercion-hierarchies/define-types! :Coercion/ISO8601->DateTime          :type/Text                     :type/DateTime)
 (coercion-hierarchies/define-types! :Coercion/ISO8601->Time              :type/Text                     :type/Time)
 
+(coercion-hierarchies/define-types! :Coercion/Integer->Boolean            :type/Integer                 :type/Boolean)
+
 (coercion-hierarchies/define-types! :Coercion/YYYYMMDDHHMMSSString->Temporal :type/Text                 :type/DateTime)
 
 (coercion-hierarchies/define-types! :Coercion/DateTime->Date  :type/DateTime :type/Date)

test/metabase/query_processor/coercion_test.clj

@@ -51,6 +51,21 @@
               (is (= res
                      (biginteger coerced-number))))))))))
 
+(deftest ^:parallel integer-to-boolean-coercion-test
+  (mt/test-drivers #{:sqlite}
+    (mt/dataset rounding-nums-db
+      (let [mp (lib.tu/merged-mock-metadata-provider
+                (mt/metadata-provider)
+                {:fields [{:id (mt/id :nums "int_col")
+                           :coercion-strategy :Coercion/Integer->Boolean
+                           :effective-type :type/Boolean}]})
+            query (-> (lib/query mp (lib.metadata/table mp (mt/id :nums)))
+                      (lib/with-fields [(lib.metadata/field mp (mt/id :nums :int_col))]))]
+        (let [rows (mt/rows (qp.store/with-metadata-provider mp
+                              (qp/process-query query)))]
+          (is (false? (ffirst rows)))
+          (is (true? (fnext rows))))))))
+
 (deftest ^:parallel float-to-integer-coercion-test
   (mt/test-drivers
     (mt/normal-drivers)

test/metabase/types/core_test.cljc

@@ -56,6 +56,7 @@
 
 (deftest ^:parallel coercion-possibilities-test
   (is (= {:type/Text    #{::Coerce-Int-To-Str}
+          :type/Boolean #{:Coercion/Integer->Boolean}
           :type/Instant #{:Coercion/UNIXNanoSeconds->DateTime
                           :Coercion/UNIXMicroSeconds->DateTime
                           :Coercion/UNIXMilliSeconds->DateTime
@@ -68,6 +69,7 @@
          (types/coercion-possibilities :type/Decimal)))
   (testing "Should work for for subtypes of a the coercion base type(s)"
     (is (= {:type/Text    #{::Coerce-Int-To-Str}
+            :type/Boolean #{:Coercion/Integer->Boolean}
             :type/Instant #{:Coercion/UNIXNanoSeconds->DateTime
                             :Coercion/UNIXMicroSeconds->DateTime
                             :Coercion/UNIXMilliSeconds->DateTime