refactor: try to condense the action in fewer steps

This should make it easier to debug/maintain.

action.yml

@@ -67,42 +67,18 @@ outputs:
 runs:
   using: 'composite'
   steps:
-    - name: Find PR (if it exists)
+    - name: Run
       id: pr-number
-      if: inputs.comment-on-pr == 'true'
+      env:
+        BASE_BRANCH: ${{ inputs.base-branch }}
+        COMMENT: ${{ inputs.comment-on-pr }}
+        DO_COMPARISON: ${{ inputs.do-comparison }}
+        GENERATE_ARTIFACT: ${{ inputs.generate-artifact }}
+        JOB_NAME: ${{ inputs.job-name }}
       run: |
-        . "$GITHUB_ACTION_PATH/scripts/utils.sh"
-
-        log 'Determine head_ref'
-        # For push & tag events it'll bet GITHUB_REF_NAME, for pull_request events it'll be GITHUB_HEAD_REF
-        head_ref=${GITHUB_REF_NAME:-$GITHUB_HEAD_REF}
-
-        log "Get PR number for $head_ref"
-        prs=$(curl -X 'GET' \
-                "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/pulls?state=open&sort=recentupdate" \
-                -H "Authorization: token $GITHUB_TOKEN" \
-                -H 'Accept: application/json')
-
-        pr_number=$(echo "$prs" |
-                jq --arg head_ref "$head_ref" '.[] | select(.head.ref == $head_ref) | .number')
-
-        # This seems to create the file???
-        log "GITHUB_OUTPUT=$GITHUB_OUTPUT"
-        log "$(ls -l "$GITHUB_OUTPUT")"
-
-        # Protect against running before a PR is made or if it is triggered on the main branch
-        if [ -z "$pr_number" ]; then
-                warn "No PR created for this commit"
-                echo "pr-number=" >> "$GIHUB_OUTPUT"
-                exit 0
-        fi
-
-        log "Retrieved index: $pr_number"
-        log "Expected PR URL: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/pulls/$pr_number"
-
-        echo "pr-number=$pr_number" >> "$GITHUB_OUTPUT"
+        "$GITHUB_ACTION_PATH/scripts/run.sh"
     - name: Find previous comment (if present)
-      # We want to generate a comment, and we we able to fin the PR number
+      # We want to generate a comment and we we able to find the PR number
       if: inputs.comment-on-pr == 'true' && steps.pr-number.outputs.pr-number != ''
       id: find-comment
       uses: https://github.com/peter-evans/find-comment@3eae4d37986fb5a8592848f6a574fdf654e61f9e # v3
@@ -110,35 +86,21 @@ runs:
         issue-number: ${{ steps.pr-number.outputs.pr-number }}
         direction: first
         body-includes: "<!-- AUTOGENERATED by nix-flake-outputs-size action -->"
-    - name: Create report
-      if: inputs.comment-on-pr == 'true' || inputs.generate-artifact == 'true'
+    - name: Create report and comment on PR
+      # We want to generate a comment and we we able to find the PR number
+      if: inputs.comment-on-pr == 'true' && steps.pr-number.outputs.pr-number != ''
       env:
         PR_ID: ${{ steps.pr-number.outputs.pr-number }}
-        COMMENT: ${{ inputs.comment-on-pr }}
         COMMENT_ID: ${{ steps.find-comment.outputs.comment-id }}
-        ARTIFACT_NAME: ${{ inputs.artifact-name }}
         DO_COMPARISON: ${{ inputs.do-comparison }}
         BASE_BRANCH: ${{ inputs.base-branch }}
-        JOB_NAME: ${{ inputs.job-name }}
       run: |
         . "$GITHUB_ACTION_PATH/scripts/utils.sh"
 
-        # Input validation
-        if [ "$DO_COMPARISON" = 'true' ] && [ -z "$JOB_NAME" ]; then
-          error 'job-name should be set if you want to generate a comparison report'
-          exit 1
-        fi
-
-        # Create Size Report
-        "$GITHUB_ACTION_PATH/scripts/create-report.sh" report.json
-
-        # Nothing else to do
-        if [ "$COMMENT" != 'true' ]; then exit 0; fi
-
         # Try to do a comparison report
         if [ "$DO_COMPARISON" = 'true' ]; then
           if "$GITHUB_ACTION_PATH/scripts/retrieve-old-report.sh" && [ -f old-report.json ]; then
-            log "Reporting on sizes and comparing to sizes in $HEAD_BRANCH"
+            log "Reporting on sizes and comparing to sizes in $BASE_BRANCH"
 
             "$GITHUB_ACTION_PATH/scripts/comment_on_pr.sh" report.json old-report.json
             exit 0

scripts/run.sh

@@ -0,0 +1,61 @@
+#!/bin/sh
+
+. "$GITHUB_ACTION_PATH/scripts/utils.sh"
+
+# Input validation
+if [ "$COMMENT" != "true" ] && [ "$GENERATE_ARTIFACT" != "true" ]; then
+  panic 'Neither comment-on-pr nor generate-artifact is set
+    note: this looks like an error; if it isn'"'"'t disable this action with "step.if"'
+fi
+
+if [ "$DO_COMPARISON" = 'true' ] && [ -z "$JOB_NAME" ]; then
+  panic 'Requested a comparison report but job-name wasn'"'"'t set'
+fi
+
+# Create Size Report (will be uploaded by the upload-artifact action)
+"$GITHUB_ACTION_PATH/scripts/create-report.sh" report.json
+
+# Nothing else to do
+if [ "$COMMENT" != "true" ]; then exit 0; fi
+
+# Find the PR for this commit so we can post a comment on it
+pr_number=
+case "$GITHUB_EVENT_NAME" in
+"pull_request")
+  pr_number=$(jq .number "$GITHUB_EVENT_PATH")
+  log "Triggered by a pull request with index: $pr_number"
+  ;;
+"push")
+  log "Triggered by a push to $GITHUB_REF_NAME autodetecting PR number"
+
+  log "Get PR number for $GITHUB_REF_NAME"
+  prs=$(curl -X 'GET' \
+    "$GITHUB_API_URL/repos/$GITHUB_REPOSITORY/pulls?state=open&sort=recentupdate" \
+    -H "Authorization: token $GITHUB_TOKEN" \
+    -H 'Accept: application/json')
+
+  log "Found these open PRs: $(echo "$prs" | jq '[.[] | .number]')"
+
+  pr_number=$(echo "$prs" |
+    jq --arg ref "$GITHUB_REF_NAME" '.[] | select(.head.ref == $ref) | .number')
+
+  # Protect against running before a PR is made or if it is triggered on the main branch
+  if [ -z "$pr_number" ]; then
+    warn "No PR created for this commit"
+    exit 0
+  fi
+
+  log "The PR we found for $GITHUB_REF_NAME is $pr_number"
+  ;;
+*)
+  panic "Unexpected event $GITHUB_EVENT_NAME for commenting on a PR, expected push or pull_request"
+  ;;
+esac
+
+log "Expected PR URL: $GITHUB_SERVER_URL/$GITHUB_REPOSITORY/pulls/$pr_number"
+
+# This seems to create the file???
+log "GITHUB_OUTPUT=$GITHUB_OUTPUT"
+log "$(ls -l "$GITHUB_OUTPUT")"
+
+echo "pr-number=$pr_number" >>"$GITHUB_OUTPUT"

scripts/utils.sh

@@ -12,6 +12,11 @@ error() {
   log "\e[0;31m[WARN]:" "$@" "\e[0m"
 }
 
+panic() {
+  error "$@"
+  exit 1
+}
+
 group() {
   echo "::group::$1"
 }