M14: harden source and artifact validation

Makefile

@@ -4,8 +4,8 @@ PDF_ENGINE ?= xelatex
 NO_SRC := $(sort $(wildcard course/no/*.md))
 EN_SRC := $(sort $(wildcard course/en/*.md))
 
-.PHONY: all html epub pdf kindle check clean
-all: check html epub pdf kindle
+.PHONY: all html epub pdf kindle check validate clean
+all: check html epub pdf kindle validate
 
 build:
 	mkdir -p build/html/no build/html/en build/epub build/pdf build/kindle
@@ -35,5 +35,8 @@ kindle: epub
 		echo 'Calibre not installed; Kindle-compatible EPUB retained.'; \
 	fi
 
+validate:
+	$(PYTHON) scripts/check_artifacts.py
+
 clean:
 	rm -rf build

scripts/check_artifacts.py

@@ -0,0 +1,53 @@
+#!/usr/bin/env python3
+from pathlib import Path
+import sys
+import zipfile
+
+errors = []
+
+required = [
+    Path("build/html/no/index.html"),
+    Path("build/html/en/index.html"),
+    Path("build/epub/edunumbers-no.epub"),
+    Path("build/epub/edunumbers-en.epub"),
+    Path("build/pdf/edunumbers-no.pdf"),
+    Path("build/pdf/edunumbers-en.pdf"),
+]
+
+for path in required:
+    if not path.is_file():
+        errors.append(f"missing artifact: {path}")
+    elif path.stat().st_size == 0:
+        errors.append(f"empty artifact: {path}")
+
+for path in required:
+    if path.suffix == ".epub" and path.is_file():
+        if not zipfile.is_zipfile(path):
+            errors.append(f"invalid EPUB ZIP container: {path}")
+        else:
+            with zipfile.ZipFile(path) as archive:
+                if "mimetype" not in archive.namelist():
+                    errors.append(f"EPUB missing mimetype entry: {path}")
+                elif archive.read("mimetype") != b"application/epub+zip":
+                    errors.append(f"EPUB has invalid mimetype: {path}")
+
+for path in required:
+    if path.suffix == ".pdf" and path.is_file():
+        with path.open("rb") as stream:
+            if stream.read(5) != b"%PDF-":
+                errors.append(f"invalid PDF header: {path}")
+
+kindle = list(Path("build/kindle").glob("*"))
+if not kindle:
+    errors.append("no Kindle artifact produced")
+for path in kindle:
+    if not path.is_file() or path.stat().st_size == 0:
+        errors.append(f"invalid Kindle artifact: {path}")
+
+if errors:
+    print("Artifact validation failed:")
+    for error in errors:
+        print(f"- {error}")
+    sys.exit(1)
+
+print(f"Artifact validation passed: {len(required)} core files + {len(kindle)} Kindle files")

scripts/check_sources.py

@@ -1,20 +1,50 @@
 #!/usr/bin/env python3
 from pathlib import Path
+import re
 import sys
 
-required = [
-    Path('README.md'), Path('COURSE.md'),
-    Path('course/no/00-introduksjon.md'),
-    Path('course/en/00-introduction.md'),
-    Path('book/metadata-no.yaml'), Path('book/metadata-en.yaml'),
-]
-missing = [str(p) for p in required if not p.is_file()]
-if missing:
-    print('Missing required M0 files:')
-    print('\n'.join(f'- {p}' for p in missing))
+errors = []
+
+for required in [
+    Path("README.md"), Path("COURSE.md"),
+    Path("book/metadata-no.yaml"), Path("book/metadata-en.yaml"),
+]:
+    if not required.is_file():
+        errors.append(f"missing required file: {required}")
+
+def chapters(directory):
+    found = {}
+    for path in Path(directory).glob("*.md"):
+        match = re.match(r"(\d\d)-", path.name)
+        if match:
+            found[int(match.group(1))] = path
+    return found
+
+no = chapters("course/no")
+en = chapters("course/en")
+
+if not no:
+    errors.append("no Norwegian chapters found")
+if not en:
+    errors.append("no English chapters found")
+
+for number in sorted(set(no) | set(en)):
+    if number not in no:
+        errors.append(f"chapter {number:02d} missing Norwegian source")
+    if number not in en:
+        errors.append(f"chapter {number:02d} missing English source")
+
+for path in list(no.values()) + list(en.values()):
+    text = path.read_text(encoding="utf-8")
+    if not text.strip():
+        errors.append(f"empty source: {path}")
+    if not re.search(r"^#\s+\S", text, re.MULTILINE):
+        errors.append(f"missing H1 heading: {path}")
+
+if errors:
+    print("Source validation failed:")
+    for error in errors:
+        print(f"- {error}")
     sys.exit(1)
-for p in Path('course').rglob('*.md'):
-    if not p.read_text(encoding='utf-8').strip():
-        print(f'Empty source: {p}')
-        sys.exit(1)
-print('M0 source checks passed')
+
+print(f"Source validation passed: {len(no)} NO + {len(en)} EN chapters")