From 07ed2de9d0f4747d5ff0a231b2f72d48d2c9bf42 Mon Sep 17 00:00:00 2001
From: Darren Burns <darren.burns@fanduel.com>
Date: Sat, 9 Nov 2019 18:42:40 +0000
Subject: [PATCH] Formatting descriptions, displaying parameterised tests in
 output

---
 tests/test_util.py | 21 ++++++++++++++++++---
 ward/suite.py      |  1 +
 ward/terminal.py   | 26 ++++++++++++--------------
 ward/testing.py    | 25 +++++++++++++++++++++++++
 ward/util.py       |  5 +++++
 5 files changed, 61 insertions(+), 17 deletions(-)

diff --git a/tests/test_util.py b/tests/test_util.py
index 597e1926..bdff864e 100644
--- a/tests/test_util.py
+++ b/tests/test_util.py
@@ -1,7 +1,7 @@
 from tests.test_suite import example_test
-from ward import expect, test, using
-from ward.testing import TestOutcome, TestResult
-from ward.util import ExitCode, get_exit_code
+from ward import expect, test, using, fixture
+from ward.testing import TestOutcome, TestResult, each
+from ward.util import ExitCode, get_exit_code, truncate
 
 
 @test(
@@ -37,3 +37,18 @@ def _(example=example_test):
     exit_code = get_exit_code(test_results)
 
     expect(exit_code).equals(ExitCode.FAILED)
+
+
+@fixture
+def s():
+    return "hello world"
+
+
+@test("truncate('{input}', num_chars={num_chars}) returns '{expected}'")
+def _(
+    input=s,
+    num_chars=each(20, 11, 10, 5),
+    expected=each(s, s, "hello w...", "he..."),
+):
+    result = truncate(input, num_chars)
+    expect(result).equals(expected)
diff --git a/ward/suite.py b/ward/suite.py
index 7ab15cc2..eb8fd03f 100644
--- a/ward/suite.py
+++ b/ward/suite.py
@@ -37,6 +37,7 @@ def generate_test_runs(self) -> Generator[TestResult, None, None]:
 
                 try:
                     resolved_vals = generated_test.resolve_args(self.cache, iteration=i)
+                    generated_test.format_description(resolved_vals)
                     generated_test(**resolved_vals)
                     outcome = (
                         TestOutcome.XPASS if marker == "XFAIL" else TestOutcome.PASS
diff --git a/ward/terminal.py b/ward/terminal.py
index ee1e84c5..817fed61 100644
--- a/ward/terminal.py
+++ b/ward/terminal.py
@@ -11,12 +11,7 @@
 from ward.expect import ExpectationFailed, Expected
 from ward.suite import Suite
 from ward.testing import TestOutcome, TestResult
-from ward.util import ExitCode, get_exit_code
-
-
-def truncate(s: str, num_chars: int) -> str:
-    suffix = "..." if len(s) > num_chars - 3 else ""
-    return s[:num_chars] + suffix
+from ward.util import ExitCode, get_exit_code, truncate
 
 
 class TestResultWriterBase:
@@ -120,11 +115,17 @@ def output_single_test_result(self, test_result: TestResult):
         colour = outcome_to_colour[test_result.outcome]
         bg = f"on_{colour}"
         padded_outcome = f" {test_result.outcome.name[:4]} "
-        if test_result.test.description:
-            sep = f":{test_result.test.line_number}: "
+
+        # If we're executing a parameterised test
+        param_meta = test_result.test.param_meta
+        if param_meta.group_size > 1:
+            iter_indicator = f" [{param_meta.instance_index + 1} of {param_meta.group_size}]"
         else:
-            sep = "."
-        mod_name = lightblack(f"{test_result.test.module_name}{sep}")
+            iter_indicator = ""
+
+        mod_name = lightblack(f"{test_result.test.module_name}:"
+                              f"{test_result.test.line_number}"
+                              f"{iter_indicator}: ")
         if (
             test_result.outcome == TestOutcome.SKIP
             or test_result.outcome == TestOutcome.XFAIL
@@ -135,10 +136,7 @@ def output_single_test_result(self, test_result: TestResult):
         else:
             reason = ""
 
-        if test_result.test.description:
-            name_or_desc = test_result.test.description
-        else:
-            name_or_desc = test_result.test.name
+        name_or_desc = test_result.test.description
         print(
             colored(padded_outcome, color="grey", on_color=bg),
             mod_name + name_or_desc,
diff --git a/ward/testing.py b/ward/testing.py
index 4b4ed3df..ef80b8d5 100644
--- a/ward/testing.py
+++ b/ward/testing.py
@@ -76,6 +76,11 @@ def generate_id():
     return uuid.uuid4().hex
 
 
+class FormatDict(dict):
+    def __missing__(self, key):
+        return "{" + key + "}"
+
+
 @dataclass
 class ParamMeta:
     instance_index: int = 0
@@ -312,6 +317,26 @@ def _unpack_resolved(self, fixture_dict: Dict[str, Any]) -> Dict[str, Any]:
                 resolved_vals[k] = arg
         return resolved_vals
 
+    def format_description(self, arg_map: Dict[str, Any]) -> str:
+        """
+        Applies any necessary string formatting to the description,
+        given a dictionary `arg_map` of values that will be injected
+        into the test.
+
+        This method will mutate the Test by updating the description.
+        Returns the newly updated description.
+        """
+        format_dict = FormatDict(**arg_map)
+        if not self.description:
+            self.description = ""
+
+        try:
+            self.description = self.description.format_map(format_dict)
+        except ValueError:
+            pass
+
+        return self.description
+
 
 # Tests declared with the name _, and with the @test decorator
 # have to be stored in here, so that they can later be retrieved.
diff --git a/ward/util.py b/ward/util.py
index afeb8563..6cd42a83 100644
--- a/ward/util.py
+++ b/ward/util.py
@@ -18,3 +18,8 @@ def get_exit_code(results: Iterable[TestResult]) -> ExitCode:
     else:
         exit_code = ExitCode.SUCCESS
     return exit_code
+
+
+def truncate(s: str, num_chars: int) -> str:
+    suffix = "..." if len(s) > num_chars else ""
+    return s[:num_chars - len(suffix)] + suffix