test: Rename SeedRand::SEED to FIXED_SEED for clarity

src/test/util/random.cpp

@@ -36,7 +36,7 @@ void SeedRandomStateForTest(SeedRand seedtype)
         return GetRandHash();
     }();
 
-    const uint256& seed{seedtype == SeedRand::SEED ? ctx_seed : uint256::ZERO};
+    const uint256& seed{seedtype == SeedRand::FIXED_SEED ? ctx_seed : uint256::ZERO};
     LogInfo("Setting random seed for current tests to %s=%s\n", RANDOM_CTX_SEED, seed.GetHex());
     MakeRandDeterministicDANGEROUS(seed);
 }

src/test/util/random.h

@@ -12,8 +12,16 @@
 #include <cstdint>
 
 enum class SeedRand {
-    ZEROS, //!< Seed with a compile time constant of zeros
+    /**
-    SEED,  //!< Use (and report) random seed from environment, or a (truly) random one.
+     * Seed with a compile time constant of zeros.
+     */
+    ZEROS,
+    /**
+     * Seed with a fixed value that never changes over the lifetime of this
+     * process. The seed is read from the RANDOM_CTX_SEED environment variable
+     * if set, otherwise generated randomly once, saved, and reused.
+     */
+    FIXED_SEED,
 };
 
 /** Seed the global RNG state for testing and log the seed value. This affects all randomness, except GetStrongRandBytes(). */

src/test/util/setup_common.cpp

@@ -154,7 +154,7 @@ BasicTestingSetup::BasicTestingSetup(const ChainType chainType, TestOpts opts)
 
     // Use randomly chosen seed for deterministic PRNG, so that (by default) test
     // data directories use a random name that doesn't overlap with other tests.
-    SeedRandomForTest(SeedRand::SEED);
+    SeedRandomForTest(SeedRand::FIXED_SEED);
 
     if (!m_node.args->IsArgSet("-testdatadir")) {
         // By default, the data directory has a random name

src/test/util/setup_common.h

@@ -68,7 +68,7 @@ struct BasicTestingSetup {
 
     FastRandomContext m_rng;
     /** Seed the global RNG state and m_rng for testing and log the seed value. This affects all randomness, except GetStrongRandBytes(). */
-    void SeedRandomForTest(SeedRand seed = SeedRand::SEED)
+    void SeedRandomForTest(SeedRand seed)
     {
         SeedRandomStateForTest(seed);
         m_rng.Reseed(GetRandHash());