fix(report): use nix eval to list the components

This is less error prone than parsing the information from `nix flake
show`.

.forgejo/workflows/check.yml

@@ -24,18 +24,17 @@ jobs:
         uses: ./
         with:
           # Create a comment on the associated PR
-          comment-on-pr: ${{ github.ref_name != 'main' }}
+          comment-on-pr: 'false'
           # Generate artifacts on main (to speed up comparisons)
           # generate-artifact: ${{ github.ref_name == 'main' }}
           # Always generate artifacts for testing purposes
           generate-artifact: 'true'
-          # Generate comparisons to main
-          do-comparison: 'true'
-          # This job's name (so we can find the artifacts)
+          # This job's name (so we can find the previous artifacts)
           job-name: report-size
   report-download-check:
     runs-on: nixos
-    needs: report-size
+    needs: report-size-push
+    if: github.event_name == 'push'
     steps:
       - name: Download previous report
         uses: https://git.salame.cl/actions/download-artifact@d8d0a99033603453ad2255e58720b460a0555e1e # v4

.forgejo/workflows/test-pr.yml

@@ -0,0 +1,33 @@
+on:
+  pull_request:
+jobs:
+  report-size-pr:
+    runs-on: nixos
+    steps:
+      - uses: "https://git.salame.cl/actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683" # v4
+      - run: nix --version
+      - name: Create Size Report
+        uses: ./
+        with:
+          # Create a comment on the associated PR
+          comment-on-pr: 'true'
+          # Generate artifacts on main (to speed up comparisons)
+          # generate-artifact: ${{ github.ref_name == 'main' }}
+          # Always generate artifacts for testing purposes
+          generate-artifact: 'true'
+          # Generate comparisons to main
+          do-comparison: 'true'
+          # Get the previous artifacts from report-size-push (since those run on main)
+          job-name: report-size
+          artifact-name: report.json
+  report-download-check-pr:
+    runs-on: nixos
+    needs: report-size-pr
+    steps:
+      - name: Download previous report
+        uses: https://git.salame.cl/actions/download-artifact@d8d0a99033603453ad2255e58720b460a0555e1e # v4
+        with:
+          name: report.json
+      - name: Verify report exists
+        run: |
+          cat report.json

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 +86,23 @@ 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 }}
+        COMMENT_ID: ${{ steps.find-comment.outputs.comment-id }}
+        DO_COMPARISON: ${{ inputs.do-comparison }}
         JOB_NAME: ${{ inputs.job-name }}
+        PR_ID: ${{ steps.pr-number.outputs.pr-number }}
       run: |
         . "$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/create-report.sh

@@ -7,24 +7,25 @@ util_path="${GITHUB_ACTION_PATH:-.}/scripts/utils.sh"
 # shellcheck source=scripts/utils.sh
 . "${util_path}"
 
-group 'Retrieving Flake information'
-flake_info=$(nix flake show --json --quiet --quiet)
-endgroup
-
 system=$(nix eval --impure --json --expr 'builtins.currentSystem')
 
-group 'Show Packages'
-packages=$(echo "$flake_info" | jq --raw-output --argjson system "$system" 'getpath(["packages", $system]) | select(. != null) | keys[]')
+# Extract the names of a flake attrset
+get_names() {
+  nix eval --json --apply builtins.attrNames "$1" 2>/dev/null | jq --raw-output '.[]'
+}
+
+group "Show Packages for $system"
+packages=$(get_names .#packages."$system")
 [ -z "$packages" ] || log "$packages"
 endgroup
 
 group 'Show Home Manager Configurations'
-hmConfigs=$(echo "$flake_info" | jq --raw-output '.homeConfigurations | select(. != null) | keys[]')
+hmConfigs=$(get_names .#homeConfigurations)
 [ -z "$hmConfigs" ] || log "$hmConfigs"
 endgroup
 
 group 'Show NixOS Configurations'
-nixosConfigs=$(echo "$flake_info" | jq --raw-output '.nixosConfigurations | select(. != null) | keys[]')
+nixosConfigs=$(get_names .#nixosConfigurations)
 [ -z "$nixosConfigs" ] || log "$nixosConfigs"
 endgroup
 
@@ -51,7 +52,7 @@ pkgs_json() {
 hm_configs_json() {
   for config in $hmConfigs; do
     log "Building $config"
-    path=$(nix build --print-out-paths ".#homeConfigurations.$config.activationPackages")
+    path=$(nix build --print-out-paths ".#homeConfigurations.$config.config.home.activationPackage")
     closure_size "$config" "$path"
   done
 }

scripts/retrieve-old-report.sh

@@ -40,7 +40,9 @@ has_report() {
 # If a base branch is not provided, use the default branch
 base_branch=${BASE_BRANCH:-$(default_branch)}
 
-if [ "$(in_private_repo)" != 'true' ] && [ "$JOB_NAME" ]; then
+if in_private_repo; then
+  warn 'Detected that this is a private repo cannot retrieve old report'
+elif [ "$JOB_NAME" ]; then
   url=$(base_report_url "$base_branch")
 
   log "Found previous run at: $url"
@@ -56,13 +58,14 @@ if [ "$(in_private_repo)" != 'true' ] && [ "$JOB_NAME" ]; then
     exit 0
   fi
   error "Failed to find previous report, expected at: $report_url"
+else
+  panic 'job-name is missing, therefore we cannot find the previous report'
 fi
 
-warn "Couldn't retrieve old report:"
-warn '    This usuially happens when running on private repos'
-warn '    or when job-name is not set.'
-warn
-warn '    See the README for more details'
+warn "Couldn't retrieve old report:
+  note: This usually happens when running on private repos or when job-name is not set.
+
+        See the README for more details"
 
 error "Falling back to slow method (checkout $base_branch and generate the report)"
 

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"
 }