Enforce photoalbum generated script drift check (5j0)

3 files changed, 48 insertions, 7 deletions

diff --git a/Justfile b/Justfile
index f397cc0..a4cf996 100644
--- a/Justfile
+++ b/Justfile
@@ -15,16 +15,49 @@ all: build
 version:
     printf '%s\n' "{{VERSION}}"
 
+[script]
 build:
     mkdir -p ./bin
+    generated=$(mktemp "./bin/.{{NAME}}.XXXXXX")
+    trap 'rm -f "$generated"' EXIT
     sed "s/PHOTOALBUMVERSION/{{VERSION}}/" \
-        "src/{{NAME}}.sh" > "./bin/{{NAME}}"
-    chmod 0755 "./bin/{{NAME}}"
+        "src/{{NAME}}.sh" > "$generated"
+    chmod 0755 "$generated"
+    if [ -f "./bin/{{NAME}}" ] && cmp -s "$generated" "./bin/{{NAME}}"; then
+        chmod 0755 "./bin/{{NAME}}"
+        rm -f "$generated"
+    else
+        mv "$generated" "./bin/{{NAME}}"
+    fi
 
-test: build
+[script]
+check-generated:
+    generated=$(mktemp)
+    trap 'rm -f "$generated"' EXIT
+    sed "s/PHOTOALBUMVERSION/{{VERSION}}/" \
+        "src/{{NAME}}.sh" > "$generated"
+    chmod 0755 "$generated"
+    if [ ! -f "./bin/{{NAME}}" ]; then
+        printf '%s\n' \
+            "ERROR: ./bin/{{NAME}} is missing; run 'just build'." >&2
+        exit 1
+    fi
+    if [ ! -x "./bin/{{NAME}}" ]; then
+        printf '%s\n' \
+            "ERROR: ./bin/{{NAME}} is not executable; run 'just build'." >&2
+        exit 1
+    fi
+    if ! cmp -s "$generated" "./bin/{{NAME}}"; then
+        printf '%s\n' \
+            "ERROR: ./bin/{{NAME}} is stale; run 'just build'." >&2
+        diff -u "./bin/{{NAME}}" "$generated" || true
+        exit 1
+    fi
+
+test: check-generated build
     bash ./tests/cli.sh
 
-install: build
+install: check-generated build
     install -d "{{DESTDIR}}{{BINDIR}}"
     install -m 0755 "./bin/{{NAME}}" "{{DESTDIR}}{{BINDIR}}/{{NAME}}"
     install -d "{{DESTDIR}}{{DATADIR}}/{{NAME}}"
@@ -43,7 +76,8 @@ deinstall:
 uninstall: deinstall
 
 clean:
-    rm -rf ./bin
+    find ./bin -maxdepth 1 -type f -name '.{{NAME}}.*' -delete \
+        2>/dev/null || true
 
 shellcheck:
     # SC1090: ShellCheck can't follow non-constant source.
diff --git a/Makefile b/Makefile
index c329da1..4159c00 100644
--- a/Makefile
+++ b/Makefile
@@ -1,4 +1,4 @@
-.PHONY: all build clean deinstall install shellcheck test uninstall version
+.PHONY: all build check-generated clean deinstall install shellcheck test uninstall version
 
-all build clean deinstall install shellcheck test uninstall version:
+all build check-generated clean deinstall install shellcheck test uninstall version:
 	just $@
diff --git a/README.md b/README.md
index e9feb9a..b828b48 100644
--- a/README.md
+++ b/README.md
@@ -13,6 +13,13 @@ just build
 sudo just install
 ```
 
+`bin/photoalbum` is a committed generated artifact for compatibility with
+existing checkouts and packaging. Its source of truth is `src/photoalbum.sh`
+rendered through the `VERSION` value in `Justfile`. Run `just build` after
+changing either file, and use `just check-generated` to verify that the tracked
+script has not drifted. `just test` and `just install` run that drift check
+before rebuilding so stale committed output is not hidden.
+
 `just install` installs `photoalbum` to `/usr/bin`, templates to
 `/usr/share/photoalbum/templates`, and the default config to
 `/etc/default/photoalbum`. Override paths with `DESTDIR`, `PREFIX`, `BINDIR`,