Merge pull request #10 from hashicorp/wrapping

Wrap `terraform plan` output in collapsible markdown

plan/entrypoint.sh

@@ -1,4 +1,27 @@
 #!/bin/sh
+
+# wrap takes some output and wraps it in a collapsible markdown section if
+# it's over $TF_ACTION_WRAP_LINES long.
+wrap() {
+  if [[ $(echo "$1" | wc -l) -gt ${TF_ACTION_WRAP_LINES:-20} ]]; then
+    echo "
+<details><summary>Show Output</summary>
+
+\`\`\`diff
+$1
+\`\`\`
+
+</details>
+"
+else
+    echo "
+\`\`\`diff
+$1
+\`\`\`
+"
+fi
+}
+
 set -e
 
 cd "${TF_ACTION_WORKING_DIR:-.}"
@@ -16,21 +39,32 @@ if [ "$TF_ACTION_COMMENT" = "1" ] || [ "$TF_ACTION_COMMENT" = "false" ]; then
     exit $SUCCESS
 fi
 
+# Build the comment we'll post to the PR.
 COMMENT=""
-
-# If not successful, post failed plan output.
 if [ $SUCCESS -ne 0 ]; then
+    OUTPUT=$(wrap "$OUTPUT")
     COMMENT="#### \`terraform plan\` Failed
-\`\`\`
-$OUTPUT
-\`\`\`"
+$OUTPUT"
 else
-    FMT_PLAN=$(echo "$OUTPUT" | sed -r -e 's/^  \+/\+/g' | sed -r -e 's/^  ~/~/g' | sed -r -e 's/^  -/-/g')
-    COMMENT="\`\`\`diff
-$FMT_PLAN
-\`\`\`"
+    # Remove "Refreshing state..." lines by only keeping output after the
+    # delimiter (72 dashes) that represents the end of the refresh stage.
+    # We do this to keep the comment output smaller.
+    if echo "$OUTPUT" | egrep '^-{72}$'; then
+        OUTPUT=$(echo "$OUTPUT" | sed -n -r '/-{72}/,/-{72}/{ /-{72}/d; p }')
+    fi
+
+    # Remove whitespace at the beginning of the line for added/modified/deleted
+    # resources so the diff markdown formatting highlights those lines.
+    OUTPUT=$(echo "$OUTPUT" | sed -r -e 's/^  \+/\+/g' | sed -r -e 's/^  ~/~/g' | sed -r -e 's/^  -/-/g')
+
+    # Call wrap to optionally wrap our output in a collapsible markdown section.
+    OUTPUT=$(wrap "$OUTPUT")
+
+    COMMENT="#### \`terraform plan\` Success
+$OUTPUT"
 fi
 
+# Post the comment.
 PAYLOAD=$(echo '{}' | jq --arg body "$COMMENT" '.body = $body')
 COMMENTS_URL=$(cat /github/workflow/event.json | jq -r .pull_request.comments_url)
 curl -s -S -H "Authorization: token $GITHUB_TOKEN" --header "Content-Type: application/json" --data "$PAYLOAD" "$COMMENTS_URL" > /dev/null