From f2eecc774fc7dd9c3a5ac787ada81c0e21917822 Mon Sep 17 00:00:00 2001
From: Nic McPhee <mcphee@morris.umn.edu>
Date: Thu, 17 Dec 2020 18:42:57 -0600
Subject: [PATCH] Add tests for `vector/_first`

These turned up an oversight in the implementation in `vector/_first` that is addressed in the next commit.
---
 .../push/instructions/vector_spec.clj         | 36 +++++++++++++++++++
 1 file changed, 36 insertions(+)

diff --git a/test/propeller/push/instructions/vector_spec.clj b/test/propeller/push/instructions/vector_spec.clj
index bec11b0..33a8009 100644
--- a/test/propeller/push/instructions/vector_spec.clj
+++ b/test/propeller/push/instructions/vector_spec.clj
@@ -6,6 +6,8 @@
    [propeller.push.state :as state]
    [propeller.push.instructions.vector :as vector]))
 
+;;; vector/_emptyvector
+
 (defn check-empty-vector
   [generator value-type]
   (let [stack-type (keyword (str "vector_" value-type))]
@@ -28,6 +30,38 @@
 (empty-vector-spec gen/boolean "boolean")
 (empty-vector-spec gen/string "string")
 
+;;; vector/_first
+
+(defn check-first
+  [generator value-type]
+  (let [stack-type (keyword (str "vector_" value-type))]
+    (prop/for-all [vect (gen/vector generator)]
+                  (let [start-state (state/push-to-stack state/empty-state
+                                                         stack-type
+                                                         vect)
+                        end-state (vector/_first stack-type start-state)]
+                    (or
+                     (and (empty? vect)
+                          (= (state/peek-stack end-state stack-type)
+                             vect))
+                     (and
+                      (= (first vect)
+                         (state/peek-stack end-state (keyword value-type)))
+                      (state/empty-stack? end-state stack-type)))))))
+
+(defmacro first-spec
+  [generator value-type]
+  `(defspec ~(symbol (str "first-spec-" value-type))
+     100
+     (check-first ~generator ~value-type)))
+
+(first-spec gen/small-integer "integer")
+(first-spec gen/double "float")
+(first-spec gen/boolean "boolean")
+(first-spec gen/string "string")
+
+;;; vector/_indexof
+
 (defn check-expected-index
   "Creates an otherwise empty Push state with the given vector on the
    appropriate vector stack (assumed to be :vector_<value-type>), and
@@ -68,6 +102,8 @@
 (indexof-spec gen/boolean "boolean")
 (indexof-spec gen/string "string")
 
+;;; vector/_subvec
+
 (defn clean-subvec-bounds
   [start stop vect-size]
   (let [start (max 0 start)