Introduce pytest (#6)

Introduce pytest with some basic tests for the CLI. We will expand on
the testing now that we have it setup.

Added it to the workflow for GitHub as well.

.github/workflows/main.yml

@@ -19,5 +19,6 @@ jobs:
         name: fzakaria
         authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
     - run: nix develop --command make lint
+    - run: nix develop --command make test
     - run: nix build --print-build-logs
     - run: nix run . -- --help

Makefile

@@ -26,4 +26,8 @@ lint:             ## Run pep8, black, mypy linters.
 # TODO(fzakaria): without pythonpath it picks up the wrong python
 # and then does not find the venv for the imports
 	pyright --pythonpath $(shell which python)
-	nixpkgs-fmt --check .
+	nixpkgs-fmt --check .
+
+.PHONY: test
+test:             ## Run pytest primarily.
+	pytest

pyproject.toml

@@ -22,6 +22,7 @@ black = "^23.7.0"
 isort = "^5.12.0"
 flake8 = "^6.1.0"
 pyright = "^1.1.325"
+pytest = "^7.4.0"
 
 [build-system]
 requires = ["poetry-core"]

sqlelf/cli.py

@@ -1,5 +1,6 @@
 import argparse
 import os
+import sys
 from functools import reduce
 
 import apsw
@@ -10,7 +11,14 @@
 from .elf import dynamic, header, instruction, section, strings, symbol
 
 
-def start():
+def start(args=sys.argv[1:], stdin=sys.stdin):
+    """
+    Start the main CLI
+
+    Args:
+        args: the command line arguments to parse
+        stdin: the stdin to use if invoking the shell
+    """
     parser = argparse.ArgumentParser(
         prog="sqlelf",
         description="Analyze ELF files with the power of SQL",
@@ -23,7 +31,7 @@ def start():
         "-s", "--sql", help="Potential SQL to execute. Omitting this enters the REPL."
     )
 
-    args = parser.parse_args()
+    args = parser.parse_args(args)
 
     # Iterate through our arguments and if one of them is a directory explode it out
     filenames: list[str] = reduce(
@@ -52,7 +60,7 @@ def start():
     strings.register(connection, binaries)
     instruction.register(connection, binaries)
 
-    shell = apsw.shell.Shell(db=connection)
+    shell = apsw.shell.Shell(db=connection, stdin=stdin)
 
     if args.sql:
         shell.process_complete_line(args.sql)

tests/test_cli.py

@@ -0,0 +1,21 @@
+from sqlelf import cli
+import pytest
+from io import StringIO
+
+def test_cli_bad_arguments():
+    with pytest.raises(SystemExit):
+        cli.start(["--does-not-exist"])
+
+def test_cli_no_arguments():
+    with pytest.raises(SystemExit):
+        cli.start([])
+
+def test_cli_single_file_arguments():
+    stdin = StringIO("")
+    cli.start(["/bin/ls"], stdin)
+
+def test_cli_prompt_single_file_arguments():
+    stdin = StringIO(".exit 56\n")
+    with pytest.raises(SystemExit) as err:
+        cli.start(["/bin/ls"], stdin)
+    assert err.value.code == 56