Make chromium test expect configured chrome binary path

The chrome binary used for pdf generation is controlled by the
CHROME_BIN_PATH environment variable, but the test in in
process_report/tests/integration/test_chromium.py expected the literal path
`/usr/bin/chromium`. This would cause the tests to fail if run in an
environment in which chromium was not installed, even if the code
successfully used an alternate path.

Author: larsks

process_report/invoices/pi_specific_invoice.py

@@ -13,6 +13,7 @@
 
 
 TEMPLATE_DIR_PATH = "process_report/templates"
+CHROME_BIN_PATH = os.environ.get("CHROME_BIN_PATH", "/usr/bin/chromium")
 
 
 logger = logging.getLogger(__name__)
@@ -120,20 +121,17 @@ def _create_html_invoice(temp_fd):
             temp_fd.flush()
 
         def _create_pdf_invoice(temp_fd_name):
-            chrome_binary_location = os.environ.get(
-                "CHROME_BIN_PATH", "/usr/bin/chromium"
-            )
-            if not os.path.exists(chrome_binary_location):
+            if not os.path.exists(CHROME_BIN_PATH):
                 sys.exit(
-                    f"Chrome binary does not exist at {chrome_binary_location}. Make sure the env var CHROME_BIN_PATH is set correctly and that Google Chrome is installed"
+                    f"Chrome binary does not exist at {CHROME_BIN_PATH}. Make sure the env var CHROME_BIN_PATH is set correctly and that Google Chrome is installed"
                 )
 
             invoice_pdf_path = (
                 f"{self.name}/{pi_instituition}_{pi}_{self.invoice_month}.pdf"
             )
             subprocess.run(
                 [
-                    chrome_binary_location,
+                    CHROME_BIN_PATH,
                     "--headless",
                     "--no-sandbox",
                     f"--print-to-pdf={invoice_pdf_path}",

process_report/tests/unit/invoices/test_pi_specific_invoice.py

@@ -3,6 +3,7 @@
 import pandas
 
 from process_report.tests import util as test_utils
+from process_report.invoices.pi_specific_invoice import CHROME_BIN_PATH
 
 
 class TestPISpecificInvoice(TestCase):
@@ -137,7 +138,7 @@ def test_export_pi(self, mock_subprocess_run, mock_path_exists, mock_filter_cols
             for i, pi_pdf_path in enumerate([pi_pdf_1, pi_pdf_2]):
                 chrome_arglist, _ = mock_subprocess_run.call_args_list[i]
                 answer_arglist = [
-                    "/usr/bin/chromium",
+                    CHROME_BIN_PATH,
                     "--headless",
                     "--no-sandbox",
                     f"--print-to-pdf={pi_pdf_path}",