website_zola: add site diff script for Hakyll vs Zola comparison

Compares built Hakyll output against Zola output, accounting for URL
structure differences (flat .html vs directory/index.html). Reports
identical, different, and missing files with inline diffs for text.

Author: agentydragon

website_zola/diff_sites.sh

@@ -0,0 +1,140 @@
+#!/usr/bin/env bash
+# Compare a Hakyll-generated site against a Zola-generated site.
+# Accounts for URL structure differences (flat .html vs directory/index.html).
+#
+# Usage: diff_sites.sh <hakyll_dir> <zola_dir>
+
+set -euo pipefail
+
+HAKYLL="${1:?Usage: diff_sites.sh <hakyll_dir> <zola_dir>}"
+ZOLA="${2:?Usage: diff_sites.sh <hakyll_dir> <zola_dir>}"
+
+# Colors
+RED='\033[0;31m'
+GREEN='\033[0;32m'
+YELLOW='\033[0;33m'
+CYAN='\033[0;36m'
+BOLD='\033[1m'
+NC='\033[0m'
+
+identical=0
+differing=0
+hakyll_only=0
+zola_only=0
+
+# Map a Hakyll relative path to the expected Zola relative path.
+hakyll_to_zola_path() {
+  local h="$1"
+  case "$h" in
+    # Top-level pages: foo.html -> foo/index.html
+    about.html) echo "about/index.html" ;;
+    found.html) echo "found/index.html" ;;
+    nfc.html) echo "nfc/index.html" ;;
+    nfc-armband.html) echo "nfc-armband/index.html" ;;
+    archive.html) echo "archive/index.html" ;;
+    # Posts: posts/slug.html -> posts/slug/index.html
+    posts/*.html)
+      local slug="${h%.html}"
+      echo "${slug}/index.html"
+      ;;
+    # These stay the same
+    index.html | atom.xml | rss.xml | robots.txt | sitemap.xml)
+      echo "$h"
+      ;;
+    # CSS: Hakyll css/default.css -> Zola default.css (compiled SASS)
+    css/default.css) echo "default.css" ;;
+    css/default.scss) echo "__SKIP__" ;; # source file, not in Zola output
+    # Everything else: try same path
+    *) echo "$h" ;;
+  esac
+}
+
+echo -e "${BOLD}=== Site Diff: Hakyll vs Zola ===${NC}"
+echo -e "Hakyll: ${HAKYLL}"
+echo -e "Zola:   ${ZOLA}"
+echo
+
+# --- Phase 1: Check Hakyll files against Zola ---
+echo -e "${BOLD}--- Hakyll files ---${NC}"
+
+while IFS= read -r hakyll_file; do
+  rel="${hakyll_file#"$HAKYLL"/}"
+  zola_rel=$(hakyll_to_zola_path "$rel")
+
+  if [[ "$zola_rel" == "__SKIP__" ]]; then
+    continue
+  fi
+
+  zola_file="${ZOLA}/${zola_rel}"
+
+  if [[ ! -f "$zola_file" ]]; then
+    echo -e "  ${YELLOW}HAKYLL-ONLY${NC}  ${rel}  (expected: ${zola_rel})"
+    ((hakyll_only++)) || true
+    continue
+  fi
+
+  # Binary or text comparison
+  case "$rel" in
+    *.html | *.xml | *.css | *.txt)
+      if diff -q <(sed 's/[[:space:]]*$//' "$hakyll_file") \
+        <(sed 's/[[:space:]]*$//' "$zola_file") &>/dev/null; then
+        echo -e "  ${GREEN}IDENTICAL${NC}    ${rel}"
+        ((identical++)) || true
+      else
+        echo -e "  ${RED}DIFFERENT${NC}    ${rel}  <->  ${zola_rel}"
+        ((differing++)) || true
+        # Show first 30 lines of diff
+        diff -u \
+          --label "hakyll/${rel}" \
+          --label "zola/${zola_rel}" \
+          <(sed 's/[[:space:]]*$//' "$hakyll_file") \
+          <(sed 's/[[:space:]]*$//' "$zola_file") \
+          | head -60 || true
+        echo
+      fi
+      ;;
+    *)
+      if cmp -s "$hakyll_file" "$zola_file"; then
+        echo -e "  ${GREEN}IDENTICAL${NC}    ${rel}"
+        ((identical++)) || true
+      else
+        echo -e "  ${RED}DIFFERENT${NC}    ${rel}  <->  ${zola_rel}  (binary)"
+        ((differing++)) || true
+      fi
+      ;;
+  esac
+done < <(find "$HAKYLL" -type f | sort)
+
+# --- Phase 2: Check for Zola-only files ---
+echo
+echo -e "${BOLD}--- Zola-only files (not in Hakyll) ---${NC}"
+
+# Build a set of expected Zola paths from Hakyll
+declare -A expected_zola_paths
+while IFS= read -r hakyll_file; do
+  rel="${hakyll_file#"$HAKYLL"/}"
+  zola_rel=$(hakyll_to_zola_path "$rel")
+  if [[ "$zola_rel" != "__SKIP__" ]]; then
+    expected_zola_paths["$zola_rel"]=1
+  fi
+done < <(find "$HAKYLL" -type f | sort)
+
+while IFS= read -r zola_file; do
+  rel="${zola_file#"$ZOLA"/}"
+  if [[ -z "${expected_zola_paths[$rel]+x}" ]]; then
+    echo -e "  ${CYAN}ZOLA-ONLY${NC}    ${rel}"
+    ((zola_only++)) || true
+  fi
+done < <(find "$ZOLA" -type f | sort)
+
+# --- Summary ---
+echo
+echo -e "${BOLD}=== Summary ===${NC}"
+echo -e "  ${GREEN}Identical${NC}:    ${identical}"
+echo -e "  ${RED}Different${NC}:    ${differing}"
+echo -e "  ${YELLOW}Hakyll-only${NC}:  ${hakyll_only}"
+echo -e "  ${CYAN}Zola-only${NC}:    ${zola_only}"
+
+if ((differing > 0 || hakyll_only > 0)); then
+  exit 1
+fi