Fix app.py and scripts/export.py CLI: switch to argparse, add --port/--host/--base-dir, fix default host, validate --since

[wpak-ai]

Summary

A CLI audit found three bugs across app.py and scripts/export.py. All are now fixed and covered by regression tests.

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Bugs fixed

Bug 1 — app.py: Default host was 0.0.0.0 (binds to all interfaces)

The server was binding to all network interfaces by default. The intended behaviour for a local-use tool is to bind to 127.0.0.1 (localhost only).

Fix: Changed hardcoded host="0.0.0.0" to host="127.0.0.1".

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Bug 2 — app.py: Manual sys.argv loop; missing --port, --host, --base-dir; hardcoded startup message

app.py used a hand-rolled while loop over sys.argv that only recognised --exclude-rules/-e. As a result:

• --help was silently ignored
• Unknown arguments were silently discarded
• Port and bind address could not be changed without editing the source
• The workspace storage path could only be overridden via the WORKSPACE_PATH environment variable, not from the command line
• The startup message was hardcoded to http://localhost:3000 regardless of actual host/port

Fix: Replaced the manual loop with argparse. Added:

• --port (default 3000)
• --host (default 127.0.0.1)
• --base-dir (overrides workspace storage path; wired to set_workspace_path_override)

Startup message is now dynamic: http://{args.host}:{args.port}.

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Bug 3 — scripts/export.py: Manual parse_args() with no --base-dir and no --since validation

The hand-rolled parse_args() had two problems:

• --since accepted any arbitrary string without validation. Passing --since weekly would silently be treated as "all" with no error, masking typos.
• No --base-dir flag to override the workspace storage path from the command line, forcing users to set WORKSPACE_PATH as an environment variable instead.

Fix: Replaced the manual loop with argparse. Added:

• --base-dir (overrides WORKSPACE_PATH env var when set)
• --since now uses choices=["all", "last"] — invalid values exit with a clear error message

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Tests added

tests/test_cli_args.py — 34 unittest tests covering every flag combination for both app.py and scripts/export.py, including all defaults, overrides, short-form flags, invalid --since rejection, --help/-h exit codes, and source-level assertions.