From 6ab0110964af9f8b39b52346e0c49dcad468c797 Mon Sep 17 00:00:00 2001
From: "Tobin C. Harding" <me@tobin.cc>
Date: Tue, 26 Mar 2024 13:38:44 +1100
Subject: [PATCH] Run fuzzer daily

Waiting for the fuzzer slows down the dev feedback loop because it makes
CI slow. We still want fuzz coverage but not in a way that slows down
devs.

Instead of running the fuzzer on every PR just run it once a nightly.

As we do for other daily jobs, rename the yaml file to make explicit
what it does.

Open questions:

- This should run for 30 minutes but I can't work out why the current
  set up only runs for a shorter time than that?
- Is this less fuzzing i.e., is 30 minutes once a day better or worse that 1
  minute 30 times?
---
 .../workflows/{fuzz.yml => cron-daily-fuzz.yml}    | 14 ++++++++------
 fuzz/fuzz.sh                                       |  2 +-
 2 files changed, 9 insertions(+), 7 deletions(-)
 rename .github/workflows/{fuzz.yml => cron-daily-fuzz.yml} (89%)

diff --git a/.github/workflows/fuzz.yml b/.github/workflows/cron-daily-fuzz.yml
similarity index 89%
rename from .github/workflows/fuzz.yml
rename to .github/workflows/cron-daily-fuzz.yml
index 3a0e4d1a..63986907 100644
--- a/.github/workflows/fuzz.yml
+++ b/.github/workflows/cron-daily-fuzz.yml
@@ -1,12 +1,12 @@
 # Automatically generated by fuzz/generate-files.sh
 name: Fuzz
-
 on:
-  push:
-    branches:
-      - master
-      - 'test-ci/**'
-  pull_request:
+  schedule:
+    # 5am every day UTC, this correlates to:
+    # - 10pm PDT
+    # - 6am CET
+    # - 4pm AEDT
+    - cron: '00 05 * * *'
 
 jobs:
   fuzz:
@@ -15,6 +15,8 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        # We only get 20 jobs at a time, we probably don't want to go
+        # over that limit with fuzzing because of the hour run time.
         fuzz_target: [
           bitcoin_deserialize_address,
           bitcoin_deserialize_block,
diff --git a/fuzz/fuzz.sh b/fuzz/fuzz.sh
index 5fc65ae6..a22e01cc 100755
--- a/fuzz/fuzz.sh
+++ b/fuzz/fuzz.sh
@@ -28,7 +28,7 @@ for targetFile in $targetFiles; do
   else
     HFUZZ_INPUT_ARGS=""
   fi
-  HFUZZ_RUN_ARGS="--run_time 30 --exit_upon_crash -v $HFUZZ_INPUT_ARGS" cargo hfuzz run "$targetName"
+  HFUZZ_RUN_ARGS="--run_time 3600 --exit_upon_crash -v $HFUZZ_INPUT_ARGS" cargo hfuzz run "$targetName"
 
   checkReport "$targetName"
 done