tools/build_defs/hash/sha256_test.sh

#!/bin/bash

# Copyright 2017 The Bazel Authors. All rights reserved.
#
# 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.

# --- begin runfiles.bash initialization v2 ---
# Copy-pasted from the Bazel Bash runfiles library v2.
set -uo pipefail; f=bazel_tools/tools/bash/runfiles/runfiles.bash
source "${RUNFILES_DIR:-/dev/null}/$f" 2>/dev/null || \
  source "$(grep -sm1 "^$f " "${RUNFILES_MANIFEST_FILE:-/dev/null}" | cut -f2- -d' ')" 2>/dev/null || \
  source "$0.runfiles/$f" 2>/dev/null || \
  source "$(grep -sm1 "^$f " "$0.runfiles_manifest" | cut -f2- -d' ')" 2>/dev/null || \
  source "$(grep -sm1 "^$f " "$0.exe.runfiles_manifest" | cut -f2- -d' ')" 2>/dev/null || \
  { echo>&2 "ERROR: cannot find $f"; exit 1; }; f=; set -e
# --- end runfiles.bash initialization v2 ---

if [[ "$(uname -s | tr [:upper:] [:lower:])" =~ msys* ]]; then
  declare -r EXE_EXT=".exe"
else
  declare -r EXE_EXT=""
fi

DIR=$(mktemp -d "${TEST_TMPDIR}/test.XXXXXXXX")
cd $DIR

# The following code produces a 120MB file (30*2^22 bytes)
cat > input.txt <<EOF
01234567890123456789012345678
EOF

cp input.txt tmp.txt
for i in {1..22}; do
  cat tmp.txt >> input.txt
  cp input.txt tmp.txt
done

"$(rlocation io_bazel/tools/build_defs/hash/sha256${EXE_EXT})" \
  "$DIR/input.txt" "$DIR/output.txt"

expected=b89e2ebd615b1d32be9cec7bf687f3a00476835fe2ea8fb560394d79f420390c
if [ "$(cat output.txt)" != "$expected" ]; then
  echo "Wrong hash $(cat output.txt); expected $expected"
  exit 1
fi