Add an end-to-end test for repeated repository garbage collection

As only a recent commit made it possible to rotate the repository
cache more than once, add a test ensuring two properties.
 - Repeated repository gc is possible and roots are taken from the
   rotated generation.
 - It is possible to fully rotate a root out.

2 files changed, 148 insertions, 0 deletions

diff --git a/test/end-to-end/just-mr/TARGETS b/test/end-to-end/just-mr/TARGETS
index 636e5383..92251a0f 100644
--- a/test/end-to-end/just-mr/TARGETS
+++ b/test/end-to-end/just-mr/TARGETS
@@ -214,6 +214,12 @@
   , "deps": [["", "mr-tool-under-test"], ["", "tool-under-test"]]
   , "keep": ["log/log-1", "log/log-2"]
   }
+, "repeated-gc":
+  { "type": ["@", "rules", "shell/test", "script"]
+  , "name": ["repeated-gc"]
+  , "test": ["repeated-gc.sh"]
+  , "deps": [["", "mr-tool-under-test"], ["", "tool-under-test"]]
+  }
 , "TESTS":
   { "type": ["@", "rules", "test", "suite"]
   , "arguments_config": ["TEST_BOOTSTRAP_JUST_MR", "TEST_COMPATIBLE_REMOTE"]
@@ -239,6 +245,7 @@
               , "foreign-file"
               , "reporting-verbosity"
               , "gc-repo"
+              , "repeated-gc"
               ]
             , { "type": "if"
               , "cond": {"type": "var", "name": "TEST_COMPATIBLE_REMOTE"}
diff --git a/test/end-to-end/just-mr/repeated-gc.sh b/test/end-to-end/just-mr/repeated-gc.sh
new file mode 100755
index 00000000..3b7bf62e
--- /dev/null
+++ b/test/end-to-end/just-mr/repeated-gc.sh
@@ -0,0 +1,141 @@
+#!/bin/sh
+# Copyright 2025 Huawei Cloud Computing Technology Co., Ltd.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+
+set -eu
+
+readonly JUST="${PWD}/bin/tool-under-test"
+readonly JUST_MR="${PWD}/bin/mr-tool-under-test"
+readonly WRKDIR="${PWD}/work"
+readonly LBR="${TEST_TMPDIR}/local-build-root"
+readonly OUT="${TEST_TMPDIR}/out"
+readonly ORIG_SRC="${TEST_TMPDIR}/orig"
+
+# Generate an archive and make the content known to CAS
+# =====================================================
+
+mkdir -p "${ORIG_SRC}"
+cd "${ORIG_SRC}"
+mkdir -p src/some/deep/directory
+echo 'some data values' > src/some/deep/directory/data.txt
+cat > src/TARGETS <<'EOF'
+{ "":
+  { "type": "generic"
+  , "outs": ["out.txt"]
+  , "deps": ["some/deep/directory/data.txt"]
+  , "cmds": ["cat some/deep/directory/data.txt | tr a-z A-Z > out.txt"]
+  }
+}
+EOF
+tar cvf source.tar src
+SOURCE_HASH=$("${JUST}" add-to-cas --local-build-root "${LBR}" source.tar)
+rm -rf source.tar src
+
+echo "Upstream hash is ${SOURCE_HASH}"
+
+# Use that archive
+# ================
+
+mkdir -p "${WRKDIR}"
+cd "${WRKDIR}"
+touch ROOT
+cat > repos.json <<EOF
+{ "repositories":
+  { "":
+    { "repository":
+      { "type": "archive"
+      , "content": "${SOURCE_HASH}"
+      , "fetch": "http://nonexistent.upstream.example.com/source.tar"
+      , "subdir": "src"
+      }
+    }
+  }
+}
+EOF
+cat repos.json
+
+CONF=$("${JUST_MR}" --norc --local-build-root "${LBR}" setup)
+cat "${CONF}"
+echo
+GIT_ROOT=$(jq -r '.repositories.""."workspace_root" | .[2]' "${CONF}")
+echo "Git root is ${GIT_ROOT}"
+echo
+
+"${JUST}" install -C "${CONF}" --local-build-root "${LBR}" \
+          -L '["env", "PATH='"${PATH}"'"]' -o "${OUT}" 2>&1
+# sanity check
+grep VALUES "${OUT}/out.txt"
+
+
+# Clean up build root: CAS/cache fully, rotate repo cache
+# =======================================================
+
+# Before rotation the git root should still exist
+[ -e "${GIT_ROOT}" ]
+"${JUST_MR}" --local-build-root "${LBR}" --just "${JUST}" gc-repo 2>&1
+# After gc rotation, the original git root should no longer exist
+[ -e "${GIT_ROOT}" ] && exit 1 || :
+
+"${JUST_MR}" --local-build-root "${LBR}" --just "${JUST}" gc 2>&1
+"${JUST_MR}" --local-build-root "${LBR}" --just "${JUST}" gc 2>&1
+
+
+# Building should nevertheless succeed, due to the old repo generation
+# =====================================================================
+
+"${JUST_MR}" --just "${JUST}" --local-build-root "${LBR}" \
+          -L '["env", "PATH='"${PATH}"'"]' install -o "${OUT}" 2>&1
+# sanity check
+grep VALUES "${OUT}/out.txt"
+rm -f "${OUT}/out.txt"
+
+
+# Repeat the whole procedure several times
+# ========================================
+
+for _ in `seq 1 5`
+do
+
+CONF=$("${JUST_MR}" --norc --local-build-root "${LBR}" setup)
+GIT_ROOT=$(jq -r '.repositories.""."workspace_root" | .[2]' "${CONF}")
+echo "Git root is ${GIT_ROOT}"
+
+[ -e "${GIT_ROOT}" ]
+"${JUST_MR}" --local-build-root "${LBR}" --just "${JUST}" gc-repo 2>&1
+[ -e "${GIT_ROOT}" ] && exit 1 || :
+
+"${JUST_MR}" --local-build-root "${LBR}" --just "${JUST}" gc 2>&1
+"${JUST_MR}" --local-build-root "${LBR}" --just "${JUST}" gc 2>&1
+"${JUST_MR}" --just "${JUST}" --local-build-root "${LBR}" \
+          -L '["env", "PATH='"${PATH}"'"]' install -o "${OUT}" 2>&1
+grep VALUES "${OUT}/out.txt"
+rm -f "${OUT}/out.txt"
+
+done
+
+# Finally demonstrate that the root was not taken from anything but the cache
+# ===========================================================================
+
+"${JUST_MR}" --local-build-root "${LBR}" --just "${JUST}" gc-repo 2>&1
+"${JUST_MR}" --local-build-root "${LBR}" --just "${JUST}" gc-repo 2>&1
+
+# after full rotation of the repository, the root should be lost
+"${JUST_MR}" --norc --local-build-root "${LBR}" -f "${OUT}/log" \
+             setup 2>&1 && exit 1 || :
+
+# sanity check: the error message should mention the fetch host
+grep nonexistent.upstream.example.com "${OUT}/log"
+
+echo OK