Fix a bug where condp could throw an exception in some cases (#1195)

Fixes #1194

Author: chrisrink10

CHANGELOG.md

@@ -16,6 +16,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Fixed
  * Fix a bug in `defn` where the `attr-map?` and function metdata were merged into a seq instead of a map, causing `macroexpand` to fail in some cases (#1186)
  * Fix a bug where `basilisp.process/exec` threw an exception when inheriting the stdout stream from the current process (#1190)
+ * Fix a bug where `condp` threw an exception in certain cases (#1194)
 
 ## [v0.3.5]
 ### Changed

src/basilisp/core.lpy

@@ -3573,16 +3573,22 @@
         (let [result    (first remaining)
               remaining (rest remaining)]
           (cond
-            (not (seq remaining)) `(throw
-                                    (python/ValueError
-                                     (str "Expected result expression for condp " {:test ~test-expr})))
-            (= result :>>)        `(let [res# ~(list pred test-expr expr)]
-                                     (if res#
-                                       (~(first remaining) res#)
-                                       (condp ~pred ~expr ~@(rest remaining))))
-            :else                 `(if ~(list pred test-expr expr)
-                                     ~result
-                                     (condp ~pred ~expr ~@remaining))))
+            (= result :>>)              `(let [res# ~(list pred test-expr expr)]
+                                           (if res#
+                                             (~(first remaining) res#)
+                                             (condp ~pred ~expr ~@(rest remaining))))
+            (seq remaining)             `(if ~(list pred test-expr expr)
+                                           ~result
+                                           (condp ~pred ~expr ~@remaining))
+            (and result
+                 (not (seq remaining))) `(if ~(list pred test-expr expr)
+                                           ~result
+                                           (throw
+                                            (python/ValueError
+                                             (str "Expected result expression for condp " {:test ~test-expr}))))
+            :else                       `(throw
+                                          (python/ValueError
+                                           (str "Expected result expression for condp " {:test ~test-expr})))))
         test-expr))))
 
 (defmacro declare

tests/basilisp/test_core_macros.lpy

@@ -416,6 +416,11 @@
 (deftest condp-test
   (testing "condp result value"
     (is (= :a (condp = "a" :a)))
+    (is (= :a (condp = "a"
+                "a" :a)))
+    (is (= :a (condp = "a"
+                "a" :a
+                :b)))
     (is (= :a (condp = "a"
                 "b" :b
                 :a)))