updated readme file

scripts/generate_example_env_file.py

@@ -0,0 +1,95 @@
+#!/usr/bin/env python3
+
+from __future__ import annotations
+
+import argparse
+import re
+from pathlib import Path
+
+ENV_ASSIGNMENT_RE = re.compile(
+    r"^(\s*(?:export\s+)?)([A-Za-z_][A-Za-z0-9_]*)(\s*=\s*)(.*)$"
+)
+
+
+def split_inline_comment(rhs: str) -> tuple[str, str]:
+    in_single = False
+    in_double = False
+    escaped = False
+
+    for i, char in enumerate(rhs):
+        if escaped:
+            escaped = False
+            continue
+
+        if char == "\\":
+            escaped = True
+            continue
+
+        if char == "'" and not in_double:
+            in_single = not in_single
+            continue
+
+        if char == '"' and not in_single:
+            in_double = not in_double
+            continue
+
+        if char == "#" and not in_single and not in_double:
+            if i == 0 or rhs[i - 1].isspace():
+                return rhs[:i], rhs[i:]
+
+    return rhs, ""
+
+
+def transform_line(line: str) -> str:
+    stripped = line.strip()
+    if stripped == "" or stripped.startswith("#"):
+        return line
+
+    newline = ""
+    raw = line
+    if line.endswith("\r\n"):
+        newline = "\r\n"
+        raw = line[:-2]
+    elif line.endswith("\n"):
+        newline = "\n"
+        raw = line[:-1]
+
+    match = ENV_ASSIGNMENT_RE.match(raw)
+    if not match:
+        return line
+
+    prefix, key, delimiter, rhs = match.groups()
+    value_part, comment_part = split_inline_comment(rhs)
+    trailing_ws = value_part[len(value_part.rstrip()) :]
+    placeholder = f"${{{{project.{key}}}}}"
+
+    return f"{prefix}{key}{delimiter}{placeholder}{trailing_ws}{comment_part}{newline}"
+
+
+def generate_example_env(source_path: Path, target_path: Path) -> None:
+    lines = source_path.read_text(encoding="utf-8").splitlines(keepends=True)
+    transformed = [transform_line(line) for line in lines]
+    target_path.write_text("".join(transformed), encoding="utf-8")
+
+
+def main() -> None:
+    parser = argparse.ArgumentParser(
+        description="Generate .env.example using ${{project.KEY}} placeholders."
+    )
+    parser.add_argument("--source", default=".env", help="Path to source .env file")
+    parser.add_argument(
+        "--target", default=".env.example", help="Path to output .env.example file"
+    )
+    args = parser.parse_args()
+
+    source_path = Path(args.source)
+    target_path = Path(args.target)
+
+    if not source_path.exists():
+        raise FileNotFoundError(f"Source env file not found: {source_path}")
+
+    generate_example_env(source_path, target_path)
+
+
+if __name__ == "__main__":
+    main()