datasette install -r requirements.txt, closes #2033

tests/test_cli.py

@@ -178,6 +178,24 @@ def test_install_upgrade(run_module, flag):
     assert sys.argv == ["pip", "install", "--upgrade", "datasette"]
 
 
+@mock.patch("datasette.cli.run_module")
+def test_install_requirements(run_module):
+    runner = CliRunner()
+    with runner.isolated_filesystem():
+        with open("requirements.txt", "w") as fp:
+            fp.write("datasette-mock-plugin\ndatasette-plugin-2")
+        runner.invoke(cli, ["install", "-r", "requirements.txt"])
+    run_module.assert_called_once_with("pip", run_name="__main__")
+    assert sys.argv == ["pip", "install", "-r", "requirements.txt"]
+
+
+def test_install_error_if_no_packages():
+    runner = CliRunner()
+    result = runner.invoke(cli, ["install"])
+    assert result.exit_code == 2
+    assert "Error: Please specify at least one package to install" in result.output
+
+
 @mock.patch("datasette.cli.run_module")
 def test_uninstall(run_module):
     runner = CliRunner()