feat: adds check-markdown.sh script to verify autogen markdown files (#1421)

* WIP

* added check-markdown.sh

* pr comments

Author: devjgm

ci/check-markdown.sh

@@ -0,0 +1,41 @@
+#!/usr/bin/env bash
+# Copyright 2020 Google LLC
+#
+# 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
+
+if [[ "${CHECK_MARKDOWN}" != "yes" ]]; then
+  echo "Skipping the generated markdown check as it is disabled for this build."
+  exit 0
+fi
+
+declare -A -r GENERATOR_MAP=(
+  ["ci/generate-markdown/generate-readme.sh"]="README.md"
+  ["ci/generate-markdown/generate-packaging.sh"]="doc/packaging.md"
+)
+
+exit_status=0
+for k in "${!GENERATOR_MAP[@]}"; do
+  generator="${k}"
+  file="${GENERATOR_MAP[${k}]}"
+  out=$(diff <("${generator}") "${file}" || true)
+  if [[ -n "${out}" ]]; then
+    echo "Did you forget to run ${generator}?"
+    echo "Unexpected diff found in ${file}:"
+    echo "$out"
+    exit_status=1
+  fi
+done
+
+exit ${exit_status}

ci/kokoro/docker/build-in-docker-cmake.sh

@@ -41,6 +41,11 @@ echo "Verify formatting $(date)"
 (cd "${PROJECT_ROOT}" ; ./ci/check-style.sh)
 echo "================================================================"
 
+echo "================================================================"
+echo "Verify markdown $(date)"
+(cd "${PROJECT_ROOT}" ; ./ci/check-markdown.sh)
+echo "================================================================"
+
 echo "================================================================"
 echo "Compiling on $(date)"
 echo "================================================================"

ci/kokoro/docker/build.sh

@@ -79,6 +79,7 @@ if [[ "${BUILD_NAME}" = "clang-tidy" ]]; then
   export CXX=clang++
   export BUILD_TYPE=Debug
   export CHECK_STYLE=yes
+  export CHECK_MARKDOWN=yes
   export GENERATE_DOCS=yes
   export CLANG_TIDY=yes
   export TEST_INSTALL=yes
@@ -326,6 +327,10 @@ docker_flags=(
     # clang-format, cmake-format, and buildifier.
     "--env" "CHECK_STYLE=${CHECK_STYLE:-}"
 
+    # If set to 'yes', the build script will verify that auto-generated
+    # markdown files are in sync.
+    "--env" "CHECK_MARKDOWN=${CHECK_MARKDOWN:-}"
+
     # If set to 'yes', the build script will configure clang-tidy. Currently
     # only the CMake builds use this flag.
     "--env" "CLANG_TIDY=${CLANG_TIDY:-}"