improve message for missing keys

src/qtoolkit/io/base.py

@@ -1,6 +1,7 @@
 from __future__ import annotations
 
 import abc
+import difflib
 import shlex
 from dataclasses import fields
 from pathlib import Path
@@ -82,9 +83,22 @@ def generate_header(self, options: dict | QResources | None) -> str:
 
         # check that all the options are present in the template
         keys = set(options.keys())
-        extra = keys.difference(template.get_identifiers())
+        all_identifiers = template.get_identifiers()
+        extra = keys.difference(all_identifiers)
         if extra:
-            msg = f"The following keys are not present in the template: {', '.join(sorted(extra))}"
+            close_matches = {}
+            for extra_val in extra:
+                m = difflib.get_close_matches(extra_val, all_identifiers, n=1)
+                if m:
+                    close_matches[extra_val] = m[0]
+            msg = (
+                f"The following keys are not present in the template: {', '.join(sorted(extra))}. "
+                f"Check the template in {type(self).__module__}.{type(self).__qualname__}.header_template"
+            )
+            if close_matches:
+                msg += "Possible replacements:"
+                for extra_val, match in close_matches.items():
+                    msg += f" {match} instead of {extra_val}."
             raise ValueError(msg)
 
         unclean_header = template.safe_substitute(options)

tests/io/test_base.py

@@ -146,7 +146,7 @@ def test_generate_header(self, scheduler):
 
         with pytest.raises(
             ValueError,
-            match=r"The following keys are not present in the template: tata, titi",
+            match=r"The following keys are not present in the template: tata, titi. Check the template in .*MyScheduler.header_template",
         ):
             res = QResources(
                 nodes=4,
@@ -155,6 +155,18 @@ def test_generate_header(self, scheduler):
             )
             scheduler.generate_header(res)
 
+        with pytest.raises(
+            ValueError,
+            match=r"The following keys are not present in the template: option32, processes-per-node. "
+            r"Check the template in .*MyScheduler.header_template.*option3 instead of option32. processes_per_node instead of processes-per-node",
+        ):
+            res = QResources(
+                nodes=4,
+                processes_per_node=16,
+                scheduler_kwargs={"option32": "xxx", "processes-per-node": "yyy"},
+            )
+            scheduler.generate_header(res)
+
     def test_generate_ids_list(self, scheduler):
         ids_list = scheduler.generate_ids_list(
             [QJob(job_id=4), QJob(job_id="job_id_abc1"), 215, "job12345"]