From 8406da28773f050e00a006e4812e3ecbf919a2a9 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Tue, 30 Jan 2024 18:31:28 +0100
Subject: [PATCH] test: Generate distinct hashes

Gen::just is the constant generator. Don't just return that!
---
 tests/unit/libutil-support/tests/hash.cc | 15 +++++++++++----
 1 file changed, 11 insertions(+), 4 deletions(-)

diff --git a/tests/unit/libutil-support/tests/hash.cc b/tests/unit/libutil-support/tests/hash.cc
index 50889cd33..51b9663b4 100644
--- a/tests/unit/libutil-support/tests/hash.cc
+++ b/tests/unit/libutil-support/tests/hash.cc
@@ -11,10 +11,17 @@ using namespace nix;
 
 Gen<Hash> Arbitrary<Hash>::arbitrary()
 {
-    Hash hash(HashAlgorithm::SHA1);
-    for (size_t i = 0; i < hash.hashSize; ++i)
-        hash.hash[i] = *gen::arbitrary<uint8_t>();
-    return gen::just(hash);
+    Hash prototype(HashAlgorithm::SHA1);
+    return
+        gen::apply(
+            [](const std::vector<uint8_t> & v) {
+                Hash hash(HashAlgorithm::SHA1);
+                assert(v.size() == hash.hashSize);
+                std::copy(v.begin(), v.end(), hash.hash);
+                return hash;
+            },
+            gen::container<std::vector<uint8_t>>(prototype.hashSize, gen::arbitrary<uint8_t>())
+        );
 }
 
 }