Add basic end-to-end test for just gc

Run build and garbage collection end to end and verify two basic
properties.
- A target used after the the last gc is still available after
  another gc, and so are all its parts, even if the output is a
  single tree.
- A target not used between to gc is purged from disk and disk
  space is not used any more.

2 files changed, 110 insertions, 0 deletions

diff --git a/test/end-to-end/gc/TARGETS b/test/end-to-end/gc/TARGETS
new file mode 100644
index 00000000..d25445de
--- /dev/null
+++ b/test/end-to-end/gc/TARGETS
@@ -0,0 +1,8 @@
+{ "basic":
+  { "type": ["@", "rules", "shell/test", "script"]
+  , "name": ["basic"]
+  , "test": ["basic.sh"]
+  , "deps": [["test/end-to-end", "tool-under-test"]]
+  }
+, "TESTS": {"type": "install", "tainted": ["test"], "deps": ["basic"]}
+}
diff --git a/test/end-to-end/gc/basic.sh b/test/end-to-end/gc/basic.sh
new file mode 100644
index 00000000..106f4b49
--- /dev/null
+++ b/test/end-to-end/gc/basic.sh
@@ -0,0 +1,102 @@
+#!/bin/sh
+# Copyright 2023 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="${PWD}/bin/tool-under-test"
+readonly LBR="${TEST_TMPDIR}/local-build-root"
+readonly TOOLS_DIR="${TEST_TMPDIR}/tools"
+readonly OUT="${TEST_TMPDIR}/out"
+
+# Have tools in the "outside environment" to later demonstrate
+# that the action was _not_ rerun.
+mkdir -p "${TOOLS_DIR}"
+cat > "${TOOLS_DIR}/tree" <<'EOF'
+#!/bin/sh
+mkdir -p $1/hello/world/tree
+echo Hello World > $1/hello/world/tree/hello.txt
+echo -n World > $1/hello/world/tree/name.txt
+EOF
+chmod 755 "${TOOLS_DIR}/tree"
+cat > "${TOOLS_DIR}/large" <<'EOF'
+#!/bin/sh
+for _ in `seq 1 10000`
+do
+  echo This is a really large file 1234567890 >> $1
+done
+EOF
+chmod 755 "${TOOLS_DIR}/large"
+
+
+touch WORKSPACE
+cat > TARGETS <<'EOF'
+{ "large":
+  { "type": "generic"
+  , "arguments_config": ["ENV"]
+  , "outs": ["out.txt"]
+  , "cmds": ["${TOOLS}/large out.txt"]
+  , "env": {"type": "var", "name": "ENV"}
+  }
+, "tree":
+  { "type": "generic"
+  , "arguments_config": ["ENV"]
+  , "out_dirs": ["out"]
+  , "cmds": ["${TOOLS}/tree out"]
+  , "env": {"type": "var", "name": "ENV"}
+  }
+, "": {"type": "install", "dirs": [["large", "out"], ["tree", "out"]]}
+}
+EOF
+
+cat TARGETS
+
+# Build to fill the cache
+"${JUST}" build --local-build-root "${LBR}" \
+          -D '{"ENV": {"TOOLS": "'${TOOLS_DIR}'"}}' 2>&1
+
+# Demonstrate that from now on, we don't build anything any more
+rm -rf "${TOOLS_DIR}"
+
+# Verify the large file is in cache
+"${JUST}" install --local-build-root "${LBR}" -o "${OUT}/out-large" \
+          -D '{"ENV": {"TOOLS": "'${TOOLS_DIR}'"}}' large 2>&1
+wc -c "${OUT}/out-large/out.txt"
+test $(cat "${OUT}/out-large/out.txt" | wc -c) -gt 100000
+
+# collect garbage
+"${JUST}" gc --local-build-root "${LBR}" 2>&1
+
+# Use the tree
+"${JUST}" build --local-build-root "${LBR}" \
+          -D '{"ENV": {"TOOLS": "'${TOOLS_DIR}'"}}' tree 2>&1
+
+# collect garbage again
+"${JUST}" gc --local-build-root "${LBR}" 2>&1
+
+# Verify the build root is now small
+tar cvf "${OUT}/root.tar" "${LBR}" 2>&1
+wc -c "${OUT}/root.tar"
+test $(cat "${OUT}/root.tar" | wc -c) -lt 100000
+
+# Verify that the tree is fully in cache
+"${JUST}" install --local-build-root "${LBR}" -o "${OUT}/out-tree" \
+          -D '{"ENV": {"TOOLS": "'${TOOLS_DIR}'"}}' tree 2>&1
+ls -R "${OUT}/out-tree"
+test -f "${OUT}/out-tree/out/hello/world/tree/hello.txt"
+test -f "${OUT}/out-tree/out/hello/world/tree/name.txt"
+test "$(cat "${OUT}/out-tree/out/hello/world/tree/name.txt")" = "World"
+
+echo OK