refactor: convert %-strings to f-strings

10 files changed, 19 insertions, 29 deletions

diff --git a/coverage/control.py b/coverage/control.py
index fb7f09c4..e1eb9add 100644
--- a/coverage/control.py
+++ b/coverage/control.py
@@ -443,9 +443,7 @@ class Coverage:
         elif dycon == "test_function":
             context_switchers = [should_start_context_test_function]
         else:
-            raise CoverageException(
-                f"Don't understand dynamic_context setting: {dycon!r}"
-            )
+            raise CoverageException(f"Don't understand dynamic_context setting: {dycon!r}")
 
         context_switchers.extend(
             plugin.dynamic_context for plugin in self._plugins.context_switchers
@@ -599,9 +597,7 @@ class Coverage:
 
         """
         if not self._started:                           # pragma: part started
-            raise CoverageException(
-                "Cannot switch context, coverage is not started"
-                )
+            raise CoverageException("Cannot switch context, coverage is not started")
 
         if self._collector.should_start_context:
             self._warn("Conflicting dynamic contexts", slug="dynamic-conflict", once=True)
diff --git a/coverage/data.py b/coverage/data.py
index 752822b7..7ba51dc8 100644
--- a/coverage/data.py
+++ b/coverage/data.py
@@ -91,7 +91,7 @@ def combine_parallel_data(data, aliases=None, data_paths=None, strict=False, kee
             pattern = os.path.join(os.path.abspath(p), localdot)
             files_to_combine.extend(glob.glob(pattern))
         else:
-            raise CoverageException(f"Couldn't combine from non-existent path '{p}'")
+            raise CoverageException(f"Couldn't combine from non-existent path {p!r}")
 
     if strict and not files_to_combine:
         raise CoverageException("No data to combine")
diff --git a/coverage/execfile.py b/coverage/execfile.py
index 66020019..80277815 100644
--- a/coverage/execfile.py
+++ b/coverage/execfile.py
@@ -278,7 +278,7 @@ def make_code_from_py(filename):
     try:
         source = get_python_source(filename)
     except (OSError, NoSource) as exc:
-        raise NoSource("No file to run: '%s'" % filename) from exc
+        raise NoSource(f"No file to run: {filename!r}") from exc
 
     code = compile_unicode(source, filename, "exec")
     return code
@@ -289,7 +289,7 @@ def make_code_from_pyc(filename):
     try:
         fpyc = open(filename, "rb")
     except OSError as exc:
-        raise NoCode("No file to run: '%s'" % filename) from exc
+        raise NoCode(f"No file to run: {filename!r}") from exc
 
     with fpyc:
         # First four bytes are a version-specific magic number.  It has to
diff --git a/coverage/inorout.py b/coverage/inorout.py
index 32eb9079..a161fa61 100644
--- a/coverage/inorout.py
+++ b/coverage/inorout.py
@@ -369,8 +369,7 @@ class InOrOut:
         if not disp.has_dynamic_filename:
             if not disp.source_filename:
                 raise CoverageException(
-                    "Plugin %r didn't set source_filename for %r" %
-                    (plugin, disp.original_filename)
+                    f"Plugin {plugin!r} didn't set source_filename for {disp.original_filename!r}"
                 )
             reason = self.check_include_omit_etc(disp.source_filename, frame)
             if reason:
@@ -487,7 +486,7 @@ class InOrOut:
         """
         mod = sys.modules.get(pkg)
         if mod is None:
-            self.warn("Module %s was never imported." % pkg, slug="module-not-imported")
+            self.warn(f"Module {pkg} was never imported.", slug="module-not-imported")
             return
 
         if module_is_namespace(mod):
@@ -496,7 +495,7 @@ class InOrOut:
             return
 
         if not module_has_file(mod):
-            self.warn("Module %s has no Python source." % pkg, slug="module-not-python")
+            self.warn(f"Module {pkg} has no Python source.", slug="module-not-python")
             return
 
         # The module was in sys.modules, and seems like a module with code, but
diff --git a/coverage/misc.py b/coverage/misc.py
index bdc0b3cf..91ccd964 100644
--- a/coverage/misc.py
+++ b/coverage/misc.py
@@ -121,7 +121,7 @@ def expensive(fn):
 
         def _wrapper(self):
             if hasattr(self, attr):
-                raise AssertionError("Shouldn't have called %s more than once" % fn.__name__)
+                raise AssertionError(f"Shouldn't have called {fn.__name__} more than once")
             setattr(self, attr, True)
             return fn(self)
         return _wrapper
@@ -245,12 +245,10 @@ def _needs_to_implement(that, func_name):
     else:
         thing = "Class"
         klass = that.__class__
-        name = "{klass.__module__}.{klass.__name__}".format(klass=klass)
+        name = f"{klass.__module__}.{klass.__name__}"
 
     raise NotImplementedError(
-        "{thing} {name!r} needs to implement {func_name}()".format(
-            thing=thing, name=name, func_name=func_name
-            )
+        f"{thing} {name!r} needs to implement {func_name}()"
         )
 
 
diff --git a/coverage/parser.py b/coverage/parser.py
index 18458147..a3a41200 100644
--- a/coverage/parser.py
+++ b/coverage/parser.py
@@ -41,7 +41,7 @@ class PythonParser:
             try:
                 self.text = get_python_source(self.filename)
             except OSError as err:
-                raise NoSource(f"No source for code: '{self.filename}': {err}") from err
+                raise NoSource(f"No source for code: {self.filename!r}: {err}") from err
 
         self.exclude = exclude
 
@@ -238,9 +238,8 @@ class PythonParser:
             else:
                 lineno = err.args[1][0]     # TokenError
             raise NotPython(
-                "Couldn't parse '%s' as Python source: '%s' at line %d" % (
-                    self.filename, err.args[0], lineno
-                )
+                f"Couldn't parse {self.filename!r} as Python source: " +
+                f"{err.args[0]!r} at line {lineno}"
             ) from err
 
         self.excluded = self.first_lines(self.raw_excluded)
diff --git a/coverage/plugin_support.py b/coverage/plugin_support.py
index 7accc56f..1b5ba8d7 100644
--- a/coverage/plugin_support.py
+++ b/coverage/plugin_support.py
@@ -45,7 +45,7 @@ class Plugins:
             coverage_init = getattr(mod, "coverage_init", None)
             if not coverage_init:
                 raise CoverageException(
-                    "Plugin module %r didn't define a coverage_init function" % module
+                    f"Plugin module {module!r} didn't define a coverage_init function"
                 )
 
             options = config.get_plugin_options(module)
diff --git a/coverage/sqldata.py b/coverage/sqldata.py
index db3ab73a..d27e12a2 100644
--- a/coverage/sqldata.py
+++ b/coverage/sqldata.py
@@ -541,7 +541,7 @@ class CoverageData(SimpleReprMixin):
                 file_id = self._file_id(filename)
                 if file_id is None:
                     raise CoverageException(
-                        f"Can't add file tracer data for unmeasured file '{filename}'"
+                        f"Can't add file tracer data for unmeasured file {filename!r}"
                     )
 
                 existing_plugin = self.file_tracer(filename)
diff --git a/coverage/tomlconfig.py b/coverage/tomlconfig.py
index 8212cfe6..203192c9 100644
--- a/coverage/tomlconfig.py
+++ b/coverage/tomlconfig.py
@@ -147,9 +147,7 @@ class TomlConfigParser:
             try:
                 re.compile(value)
             except re.error as e:
-                raise CoverageException(
-                    f"Invalid [{name}].{option} value {value!r}: {e}"
-                ) from e
+                raise CoverageException(f"Invalid [{name}].{option} value {value!r}: {e}") from e
         return values
 
     def getint(self, section, option):
diff --git a/tests/goldtest.py b/tests/goldtest.py
index 7321166c..cd946efb 100644
--- a/tests/goldtest.py
+++ b/tests/goldtest.py
@@ -109,7 +109,7 @@ def compare(
         for f in actual_only:
             save_mismatch(f)
 
-    assert not text_diff, "Files differ: %s" % '\n'.join(text_diff)
+    assert not text_diff, "Files differ: " + "\n".join(text_diff)
 
     assert not expected_only, f"Files in {expected_dir} only: {expected_only}"
     if not actual_extra:
@@ -152,7 +152,7 @@ def contains_any(filename, *strlist):
             return
 
     assert False, (                         # pragma: only failure
-        "Missing content in %s: %r [1 of %d]" % (filename, strlist[0], len(strlist),)
+        f"Missing content in {filename}: {strlist[0]!r} [1 of {len(strlist)}]"
     )