Comment with dependency diff

CHANGELOG.md

@@ -38,7 +38,7 @@ _None._
 
 ### New Features
 
-_None._
+- Add a script for commenting dependencies diff on PRs in Android projects [#120]
 
 ### Bug Fixes
 

bin/comment_on_pr

@@ -126,20 +126,29 @@ $comment_body_id
 $arg_pr_comment
 EOF
 )
-json_payload=$(jq -c --null-input --arg body "$comment_body" '{body: $body}')
+
+# Write the comment body to a temporary file to fix possible "Argument list too long" error
+comment_body_file=$(mktemp)
+echo "$comment_body" > "$comment_body_file"
+
+json_payload_file=$(mktemp)
+jq -c --null-input \
+  --rawfile body "$comment_body_file" \
+  '{ body: $body }' \
+  > "$json_payload_file"
 
 if [[ -n "$existing_comment_id" && "$opt_if_exist" == "update" ]]; then
     echo "Update the existing comment: $existing_comment_id"
     github_api "$issues_endpoint/comments/$existing_comment_id" \
         --fail-with-body -X PATCH \
         -H "Content-Type: application/json" \
-        -d "${json_payload}"
+        --data-binary @"$json_payload_file"
 elif [[ -n "$arg_pr_comment" ]]; then
     echo "Post a new comment"
     github_api "$issues_endpoint/${BUILDKITE_PULL_REQUEST}/comments" \
         --fail-with-body -X POST \
         -H "Content-Type: application/json" \
-        -d "${json_payload}"
+        --data-binary @"$json_payload_file"
 else
     # No comment body was given in CLI, so no new comment to post
     echo "No new comment to post"

bin/comment_with_dependency_diff

@@ -0,0 +1,181 @@
+#!/bin/bash
+
+# This script is used in a Buildkite CI pipeline to analyze and comment on dependency changes in a
+# GitHub pull request (PR). It compares the Gradle project dependencies and build environment between the
+# base branch and the head branch to identify changes caused by updates to Gradle files.
+#
+# Usage:
+#    ./comment_with_dependency_diff <MODULE> <CONFIGURATION>
+#
+# Parameters:
+#    <MODULE>        : The Gradle module whose dependencies will be checked.
+#    <CONFIGURATION> : The Gradle configuration to inspect for dependencies (e.g., "runtimeClasspath").
+#
+# Steps:
+# 1. The script fetches the base branch of the PR and merges it into the head branch.
+# 2. It generates the dependency and build environment reports for both the base and head branches.
+# 3. The script compares these reports to detect any changes in the project's dependencies.
+# 4. If changes are found, the script creates a comment on the GitHub PR with the results.
+# 5. If no changes are detected, the script exits without posting any comment.
+#
+# Notes:
+# - The GitHub token must be set via the environment variable `GITHUB_TOKEN` to authenticate API requests.
+# - The comment on the PR will include a summary of changes and a detailed list in expandable sections.
+# - A jar file `dependency-tree-diff.jar` is downloaded and executed to perform the dependency diff.
+#
+# Example:
+#    ./comment_with_dependency_diff app release
+#
+# This will analyze the `app` module with the `release` configuration and post the result to the PR.
+
+set -euo pipefail
+
+MODULE="${1:-}"
+CONFIGURATION="${2:-}"
+
+if [ -z "$MODULE" ] || [ -z "$CONFIGURATION" ]; then
+  echo "Not enough arguments provided. Usage: ./comment_with_dependency_diff <MODULE> <CONFIGURATION>"
+  exit 1
+fi
+
+if [ "${BUILDKITE_PULL_REQUEST:-false}" == "false" ]; then
+  echo "This script should only be called on pull requests. Be sure to set \`if: build.pull_request.id != null\` on the step invoking it in your Buildkite pipeline"
+  exit 2
+fi
+
+DIFF_DEPENDENCIES_FOLDER="./build/reports/diff"
+BASE_BRANCH_DEPENDENCIES_FILE="$DIFF_DEPENDENCIES_FOLDER/base_branch_dependencies.txt"
+HEAD_BRANCH_DEPENDENCIES_FILE="$DIFF_DEPENDENCIES_FOLDER/head_branch_dependencies.txt"
+BASE_BRANCH_BUILD_ENV_FILE="$DIFF_DEPENDENCIES_FOLDER/base_branch_build_env.txt"
+HEAD_BRANCH_BUILD_ENV_FILE="$DIFF_DEPENDENCIES_FOLDER/head_branch_build_env.txt"
+DIFF_DEPENDENCIES_FILE="$DIFF_DEPENDENCIES_FOLDER/diff_dependencies.txt"
+DIFF_BUILD_ENV_FILE="$DIFF_DEPENDENCIES_FOLDER/diff_build_env.txt"
+
+DEPENDENCY_TREE_VERSION="1.2.1"
+DEPENDENCY_TREE_CHECKSUM="39c50f22cd4211a3e52afec43120b7fdf90f9890"
+
+git config --global user.email "[email protected]"
+git config --global user.name "Dependency Tree Diff Tool"
+
+echo "--> Starting the check"
+BASE_BRANCH=$BUILDKITE_PULL_REQUEST_BASE_BRANCH
+echo "--> Base branch is $BASE_BRANCH"
+
+git merge "origin/$BASE_BRANCH" --no-edit
+
+if (git diff --name-status "origin/$BASE_BRANCH" | grep -E "\.gradle(\.kts)?|\.toml" --quiet); then
+    echo "Gradle files have been changed. Looking for caused dependency changes"
+else
+    echo "Gradle files haven't been changed. There is no need to run the diff"
+    exit 0
+fi
+
+mkdir -p "$DIFF_DEPENDENCIES_FOLDER"
+
+echo "--> Generating dependencies to the file $HEAD_BRANCH_DEPENDENCIES_FILE"
+./gradlew :"$MODULE":dependencies --configuration "$CONFIGURATION" >$HEAD_BRANCH_DEPENDENCIES_FILE
+
+echo "--> Generating build environment dependencies for the head branch"
+./gradlew buildEnvironment >$HEAD_BRANCH_BUILD_ENV_FILE
+
+echo "--> Generating dependencies to the file $BASE_BRANCH_DEPENDENCIES_FILE"
+
+if ! git diff --quiet; then
+  echo "Changes detected. Stashing and continuing with the script"
+  git diff
+  git stash
+fi
+
+git checkout "$BASE_BRANCH"
+./gradlew :"$MODULE":dependencies --configuration "$CONFIGURATION" >$BASE_BRANCH_DEPENDENCIES_FILE
+
+echo "--> Generating build environment dependencies for the base branch"
+./gradlew buildEnvironment >$BASE_BRANCH_BUILD_ENV_FILE
+
+git checkout "-"
+
+echo "--> Downloading dependency-tree-diff.jar"
+curl -v -L "https://github.com/JakeWharton/dependency-tree-diff/releases/download/$DEPENDENCY_TREE_VERSION/dependency-tree-diff.jar" -o dependency-tree-diff.jar
+sha=$(sha1sum dependency-tree-diff.jar | cut -d' ' -f1)
+if [[ $sha != "$DEPENDENCY_TREE_CHECKSUM" ]]; then
+  echo "dependency-tree-diff.jar file has unexpected sha1"
+  exit 1
+fi
+chmod +x dependency-tree-diff.jar
+
+echo "--> Running dependency-tree-diff.jar"
+./dependency-tree-diff.jar $BASE_BRANCH_DEPENDENCIES_FILE $HEAD_BRANCH_DEPENDENCIES_FILE >$DIFF_DEPENDENCIES_FILE
+
+./dependency-tree-diff.jar $BASE_BRANCH_BUILD_ENV_FILE $HEAD_BRANCH_BUILD_ENV_FILE >$DIFF_BUILD_ENV_FILE
+
+generate_project_dependencies_comment_body() {
+  cat <<EOF
+
+The following changes in project dependencies were detected (configuration \`$CONFIGURATION\`):
+
+<details><summary>expand</summary>
+
+\`\`\`diff
+$(cat "$DIFF_DEPENDENCIES_FILE")
+\`\`\`
+
+</details>
+
+
+EOF
+}
+
+generate_build_dependencies_comment_body() {
+  cat <<EOF
+
+The following changes in the build classpath were detected:
+
+<details><summary>expand</summary>
+
+\`\`\`diff
+$(cat "$DIFF_BUILD_ENV_FILE")
+\`\`\`
+
+</details>
+
+EOF
+}
+
+if [ -n "$DIFF_DEPENDENCIES_FILE" ] || [ -n "$DIFF_BUILD_ENV_FILE" ]; then
+  echo "--> Commenting result to GitHub"
+
+  # Create or clear the comment body file
+  COMMENT_FILE="$DIFF_DEPENDENCIES_FOLDER/comment_body.txt"
+  true > $COMMENT_FILE  # 'true' used to clear the file as a no-op
+
+  append_content() {
+    local header="$1"
+    local content="$2"
+    local github_comment_max_size=65536
+    local warning_message="Content exceeds $github_comment_max_size characters. [Navigate to Buildkite build artifacts](${BUILDKITE_BUILD_URL}#${BUILDKITE_JOB_ID}) to see details."
+
+    local current_size
+    current_size=$(wc -c < "$COMMENT_FILE")
+
+    # Calculate if there's enough space for the content and header
+    if (( current_size + ${#header} + ${#content} > github_comment_max_size - ${#warning_message} )); then
+      printf "%s\n" "$warning_message" > $COMMENT_FILE
+      return
+    fi
+
+    printf "\n%s\n" "$header" >> $COMMENT_FILE
+    printf "%s\n" "$content" >> $COMMENT_FILE
+  }
+
+  if [ -s "$DIFF_DEPENDENCIES_FILE" ]; then
+    append_content "## Project dependencies changes" "$(generate_project_dependencies_comment_body)"
+  fi
+
+  if [ -s "$DIFF_BUILD_ENV_FILE" ]; then
+    append_content "## Build environment changes" "$(generate_build_dependencies_comment_body)"
+  fi
+
+  comment_on_pr --id "dependency-diff" --if-exist update "$COMMENT_FILE"
+else
+  comment_on_pr --id "dependency-diff" --if-exist delete
+fi