manual cleanup

10 files changed, 103 insertions, 164 deletions

diff --git a/tests/test_arguments.py b/tests/test_arguments.py
index 85ba212..0b510c0 100644
--- a/tests/test_arguments.py
+++ b/tests/test_arguments.py
@@ -13,15 +13,12 @@ def test_nargs_star(runner):
     @click.argument("src", nargs=-1)
     @click.argument("dst")
     def copy(src, dst):
-        click.echo("src=%s" % "|".join(src))
-        click.echo("dst=%s" % dst)
+        click.echo("src={}".format("|".join(src)))
+        click.echo("dst={}".format(dst))
 
     result = runner.invoke(copy, ["foo.txt", "bar.txt", "dir"])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "src=foo.txt|bar.txt",
-        "dst=dir",
-    ]
+    assert result.output.splitlines() == ["src=foo.txt|bar.txt", "dst=dir"]
 
 
 def test_nargs_default(runner):
@@ -38,15 +35,12 @@ def test_nargs_tup(runner):
     @click.argument("name", nargs=1)
     @click.argument("point", nargs=2, type=click.INT)
     def copy(name, point):
-        click.echo("name=%s" % name)
-        click.echo("point=%d/%d" % point)
+        click.echo("name={}".format(name))
+        click.echo("point={0[0]}/{0[1]}".format(point))
 
     result = runner.invoke(copy, ["peter", "1", "2"])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "name=peter",
-        "point=1/2",
-    ]
+    assert result.output.splitlines() == ["name=peter", "point=1/2"]
 
 
 def test_nargs_tup_composite(runner):
@@ -62,13 +56,11 @@ def test_nargs_tup_composite(runner):
         @click.command()
         @click.argument("item", **opts)
         def copy(item):
-            click.echo("name=%s id=%d" % item)
+            click.echo("name={0[0]} id={0[1]:d}".format(item))
 
         result = runner.invoke(copy, ["peter", "1"])
         assert not result.exception
-        assert result.output.splitlines() == [
-            "name=peter id=1",
-        ]
+        assert result.output.splitlines() == ["name=peter id=1"]
 
 
 def test_nargs_err(runner):
@@ -203,7 +195,7 @@ def test_empty_nargs(runner):
     @click.command()
     @click.argument("arg", nargs=-1)
     def cmd(arg):
-        click.echo("arg:" + "|".join(arg))
+        click.echo("arg:{}".format("|".join(arg)))
 
     result = runner.invoke(cmd, [])
     assert result.exit_code == 0
@@ -212,22 +204,22 @@ def test_empty_nargs(runner):
     @click.command()
     @click.argument("arg", nargs=-1, required=True)
     def cmd2(arg):
-        click.echo("arg:" + "|".join(arg))
+        click.echo("arg:{}".format("|".join(arg)))
 
     result = runner.invoke(cmd2, [])
     assert result.exit_code == 2
-    assert 'Missing argument "ARG..."' in result.output
+    assert "Missing argument 'ARG...'" in result.output
 
 
 def test_missing_arg(runner):
     @click.command()
     @click.argument("arg")
     def cmd(arg):
-        click.echo("arg:" + arg)
+        click.echo("arg:{}".format(arg))
 
     result = runner.invoke(cmd, [])
     assert result.exit_code == 2
-    assert 'Missing argument "ARG".' in result.output
+    assert "Missing argument 'ARG'." in result.output
 
 
 def test_missing_argument_string_cast():
@@ -260,18 +252,10 @@ def test_eat_options(runner):
         click.echo(f)
 
     result = runner.invoke(cmd, ["--", "-foo", "bar"])
-    assert result.output.splitlines() == [
-        "-foo",
-        "bar",
-        "",
-    ]
+    assert result.output.splitlines() == ["-foo", "bar", ""]
 
     result = runner.invoke(cmd, ["-f", "-x", "--", "-foo", "bar"])
-    assert result.output.splitlines() == [
-        "-foo",
-        "bar",
-        "-x",
-    ]
+    assert result.output.splitlines() == ["-foo", "bar", "-x"]
 
 
 def test_nargs_star_ordering(runner):
@@ -284,11 +268,7 @@ def test_nargs_star_ordering(runner):
             click.echo(arg)
 
     result = runner.invoke(cmd, ["a", "b", "c"])
-    assert result.output.splitlines() == [
-        PY2 and "(u'a',)" or "('a',)",
-        "b",
-        "c",
-    ]
+    assert result.output.splitlines() == ["(u'a',)" if PY2 else "('a',)", "b", "c"]
 
 
 def test_nargs_specified_plus_star_ordering(runner):
@@ -302,9 +282,9 @@ def test_nargs_specified_plus_star_ordering(runner):
 
     result = runner.invoke(cmd, ["a", "b", "c", "d", "e", "f"])
     assert result.output.splitlines() == [
-        PY2 and "(u'a', u'b', u'c')" or "('a', 'b', 'c')",
+        "(u'a', u'b', u'c')" if PY2 else "('a', 'b', 'c')",
         "d",
-        PY2 and "(u'e', u'f')" or "('e', 'f')",
+        "(u'e', u'f')" if PY2 else "('e', 'f')",
     ]
 
 
diff --git a/tests/test_basic.py b/tests/test_basic.py
index 59566cb..f07b6d1 100644
--- a/tests/test_basic.py
+++ b/tests/test_basic.py
@@ -82,7 +82,7 @@ def test_basic_option(runner):
     @click.command()
     @click.option("--foo", default="no value")
     def cli(foo):
-        click.echo("FOO:[%s]" % foo)
+        click.echo(u"FOO:[{}]".format(foo))
 
     result = runner.invoke(cli, [])
     assert not result.exception
@@ -109,7 +109,7 @@ def test_int_option(runner):
     @click.command()
     @click.option("--foo", default=42)
     def cli(foo):
-        click.echo("FOO:[%s]" % (foo * 2))
+        click.echo("FOO:[{}]".format(foo * 2))
 
     result = runner.invoke(cli, [])
     assert not result.exception
@@ -121,7 +121,7 @@ def test_int_option(runner):
 
     result = runner.invoke(cli, ["--foo=bar"])
     assert result.exception
-    assert 'Invalid value for "--foo": bar is not a valid integer' in result.output
+    assert "Invalid value for '--foo': bar is not a valid integer" in result.output
 
 
 def test_uuid_option(runner):
@@ -131,7 +131,7 @@ def test_uuid_option(runner):
     )
     def cli(u):
         assert type(u) is uuid.UUID
-        click.echo("U:[%s]" % u)
+        click.echo("U:[{}]".format(u))
 
     result = runner.invoke(cli, [])
     assert not result.exception
@@ -143,7 +143,7 @@ def test_uuid_option(runner):
 
     result = runner.invoke(cli, ["--u=bar"])
     assert result.exception
-    assert 'Invalid value for "--u": bar is not a valid UUID value' in result.output
+    assert "Invalid value for '--u': bar is not a valid UUID value" in result.output
 
 
 def test_float_option(runner):
@@ -151,7 +151,7 @@ def test_float_option(runner):
     @click.option("--foo", default=42, type=click.FLOAT)
     def cli(foo):
         assert type(foo) is float
-        click.echo("FOO:[%s]" % foo)
+        click.echo("FOO:[{}]".format(foo))
 
     result = runner.invoke(cli, [])
     assert not result.exception
@@ -163,7 +163,7 @@ def test_float_option(runner):
 
     result = runner.invoke(cli, ["--foo=bar"])
     assert result.exception
-    assert 'Invalid value for "--foo": bar is not a valid float' in result.output
+    assert "Invalid value for '--foo': bar is not a valid float" in result.output
 
 
 def test_boolean_option(runner):
@@ -182,7 +182,7 @@ def test_boolean_option(runner):
         assert result.output == "False\n"
         result = runner.invoke(cli, [])
         assert not result.exception
-        assert result.output == "%s\n" % default
+        assert result.output == "{}\n".format(default)
 
     for default in True, False:
 
@@ -193,10 +193,10 @@ def test_boolean_option(runner):
 
         result = runner.invoke(cli, ["--flag"])
         assert not result.exception
-        assert result.output == "%s\n" % (not default)
+        assert result.output == "{}\n".format(not default)
         result = runner.invoke(cli, [])
         assert not result.exception
-        assert result.output == "%s\n" % (default)
+        assert result.output == "{}\n".format(default)
 
 
 def test_boolean_conversion(runner):
@@ -219,7 +219,7 @@ def test_boolean_conversion(runner):
 
         result = runner.invoke(cli, [])
         assert not result.exception
-        assert result.output == "%s\n" % default
+        assert result.output == "{}\n".format(default)
 
 
 def test_file_option(runner):
@@ -281,7 +281,7 @@ def test_file_lazy_mode(runner):
         result_in = runner.invoke(input_non_lazy, ["--file=example.txt"])
         assert result_in.exit_code == 2
         assert (
-            'Invalid value for "--file": Could not open file: example.txt'
+            "Invalid value for '--file': Could not open file: example.txt"
             in result_in.output
         )
 
@@ -303,22 +303,17 @@ def test_path_option(runner):
             assert f.read() == b"meh\n"
 
         result = runner.invoke(write_to_dir, ["-O", "test/foo.txt"])
-        assert (
-            'Invalid value for "-O": Directory "test/foo.txt" is a file.'
-            in result.output
-        )
+        assert "is a file" in result.output
 
     @click.command()
     @click.option("-f", type=click.Path(exists=True))
     def showtype(f):
-        click.echo("is_file=%s" % os.path.isfile(f))
-        click.echo("is_dir=%s" % os.path.isdir(f))
+        click.echo("is_file={}".format(os.path.isfile(f)))
+        click.echo("is_dir={}".format(os.path.isdir(f)))
 
     with runner.isolated_filesystem():
         result = runner.invoke(showtype, ["-f", "xxx"])
-        assert (
-            'Error: Invalid value for "-f": Path "xxx" does not exist' in result.output
-        )
+        assert "does not exist" in result.output
 
         result = runner.invoke(showtype, ["-f", "."])
         assert "is_file=False" in result.output
@@ -327,7 +322,7 @@ def test_path_option(runner):
     @click.command()
     @click.option("-f", type=click.Path())
     def exists(f):
-        click.echo("exists=%s" % os.path.exists(f))
+        click.echo("exists={}".format(os.path.exists(f)))
 
     with runner.isolated_filesystem():
         result = runner.invoke(exists, ["-f", "xxx"])
@@ -350,8 +345,8 @@ def test_choice_option(runner):
     result = runner.invoke(cli, ["--method=meh"])
     assert result.exit_code == 2
     assert (
-        'Invalid value for "--method": invalid choice: meh. '
-        "(choose from foo, bar, baz)" in result.output
+        "Invalid value for '--method': invalid choice: meh."
+        " (choose from foo, bar, baz)" in result.output
     )
 
     result = runner.invoke(cli, ["--help"])
@@ -375,9 +370,9 @@ def test_datetime_option_default(runner):
     result = runner.invoke(cli, ["--start_date=2015-09"])
     assert result.exit_code == 2
     assert (
-        'Invalid value for "--start_date": '
-        "invalid datetime format: 2015-09. "
-        "(choose from %Y-%m-%d, %Y-%m-%dT%H:%M:%S, %Y-%m-%d %H:%M:%S)"
+        "Invalid value for '--start_date':"
+        " invalid datetime format: 2015-09."
+        " (choose from %Y-%m-%d, %Y-%m-%dT%H:%M:%S, %Y-%m-%d %H:%M:%S)"
     ) in result.output
 
     result = runner.invoke(cli, ["--help"])
@@ -410,7 +405,7 @@ def test_int_range_option(runner):
     result = runner.invoke(cli, ["--x=6"])
     assert result.exit_code == 2
     assert (
-        'Invalid value for "--x": 6 is not in the valid range of 0 to 5.\n'
+        "Invalid value for '--x': 6 is not in the valid range of 0 to 5.\n"
         in result.output
     )
 
@@ -445,7 +440,7 @@ def test_float_range_option(runner):
     result = runner.invoke(cli, ["--x=6.0"])
     assert result.exit_code == 2
     assert (
-        'Invalid value for "--x": 6.0 is not in the valid range of 0 to 5.\n'
+        "Invalid value for '--x': 6.0 is not in the valid range of 0 to 5.\n"
         in result.output
     )
 
@@ -475,7 +470,7 @@ def test_required_option(runner):
 
     result = runner.invoke(cli, [])
     assert result.exit_code == 2
-    assert 'Missing option "--foo"' in result.output
+    assert "Missing option '--foo'" in result.output
 
 
 def test_evaluation_order(runner):
diff --git a/tests/test_chain.py b/tests/test_chain.py
index 6aa452c..c227270 100644
--- a/tests/test_chain.py
+++ b/tests/test_chain.py
@@ -7,8 +7,9 @@ import click
 
 def debug():
     click.echo(
-        "%s=%s"
-        % (sys._getframe(1).f_code.co_name, "|".join(click.get_current_context().args),)
+        "{}={}".format(
+            sys._getframe(1).f_code.co_name, "|".join(click.get_current_context().args)
+        )
     )
 
 
@@ -76,19 +77,16 @@ def test_chaining_with_options(runner):
     @cli.command("sdist")
     @click.option("--format")
     def sdist(format):
-        click.echo("sdist called %s" % format)
+        click.echo("sdist called {}".format(format))
 
     @cli.command("bdist")
     @click.option("--format")
     def bdist(format):
-        click.echo("bdist called %s" % format)
+        click.echo("bdist called {}".format(format))
 
     result = runner.invoke(cli, ["bdist", "--format=1", "sdist", "--format=2"])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "bdist called 1",
-        "sdist called 2",
-    ]
+    assert result.output.splitlines() == ["bdist called 1", "sdist called 2"]
 
 
 def test_chaining_with_arguments(runner):
@@ -99,19 +97,16 @@ def test_chaining_with_arguments(runner):
     @cli.command("sdist")
     @click.argument("format")
     def sdist(format):
-        click.echo("sdist called %s" % format)
+        click.echo("sdist called {}".format(format))
 
     @cli.command("bdist")
     @click.argument("format")
     def bdist(format):
-        click.echo("bdist called %s" % format)
+        click.echo("bdist called {}".format(format))
 
     result = runner.invoke(cli, ["bdist", "1", "sdist", "2"])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "bdist called 1",
-        "sdist called 2",
-    ]
+    assert result.output.splitlines() == ["bdist called 1", "sdist called 2"]
 
 
 def test_pipeline(runner):
@@ -146,24 +141,15 @@ def test_pipeline(runner):
 
     result = runner.invoke(cli, ["-i", "-"], input="foo\nbar")
     assert not result.exception
-    assert result.output.splitlines() == [
-        "foo",
-        "bar",
-    ]
+    assert result.output.splitlines() == ["foo", "bar"]
 
     result = runner.invoke(cli, ["-i", "-", "strip"], input="foo \n bar")
     assert not result.exception
-    assert result.output.splitlines() == [
-        "foo",
-        "bar",
-    ]
+    assert result.output.splitlines() == ["foo", "bar"]
 
     result = runner.invoke(cli, ["-i", "-", "strip", "uppercase"], input="foo \n bar")
     assert not result.exception
-    assert result.output.splitlines() == [
-        "FOO",
-        "BAR",
-    ]
+    assert result.output.splitlines() == ["FOO", "BAR"]
 
 
 def test_args_and_chain(runner):
@@ -185,12 +171,7 @@ def test_args_and_chain(runner):
 
     result = runner.invoke(cli, ["a", "b", "c"])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "cli=",
-        "a=",
-        "b=",
-        "c=",
-    ]
+    assert result.output.splitlines() == ["cli=", "a=", "b=", "c="]
 
 
 def test_multicommand_arg_behavior(runner):
@@ -211,7 +192,7 @@ def test_multicommand_arg_behavior(runner):
     @click.group(chain=True)
     @click.argument("arg")
     def cli(arg):
-        click.echo("cli:%s" % arg)
+        click.echo("cli:{}".format(arg))
 
     @cli.command()
     def a():
@@ -219,10 +200,7 @@ def test_multicommand_arg_behavior(runner):
 
     result = runner.invoke(cli, ["foo", "a"])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "cli:foo",
-        "a",
-    ]
+    assert result.output.splitlines() == ["cli:foo", "a"]
 
 
 @pytest.mark.xfail
@@ -249,9 +227,4 @@ def test_multicommand_chaining(runner):
 
     result = runner.invoke(cli, ["l1a", "l2a", "l1b"])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "cli=",
-        "l1a=",
-        "l2a=",
-        "l1b=",
-    ]
+    assert result.output.splitlines() == ["cli=", "l1a=", "l2a=", "l1b="]
diff --git a/tests/test_commands.py b/tests/test_commands.py
index bcb30bd..1d99218 100644
--- a/tests/test_commands.py
+++ b/tests/test_commands.py
@@ -26,7 +26,7 @@ def test_other_command_forward(runner):
     @cli.command()
     @click.option("--count", default=1)
     def test(count):
-        click.echo("Count: %d" % count)
+        click.echo("Count: {:d}".format(count))
 
     @cli.command()
     @click.option("--count", default=1)
@@ -102,7 +102,7 @@ def test_group_with_args(runner):
     @click.group()
     @click.argument("obj")
     def cli(obj):
-        click.echo("obj=%s" % obj)
+        click.echo("obj={}".format(obj))
 
     @cli.command()
     def move():
@@ -211,7 +211,7 @@ def test_object_propagation(runner):
         @cli.command()
         @click.pass_context
         def sync(ctx):
-            click.echo("Debug is %s" % (ctx.obj["DEBUG"] and "on" or "off"))
+            click.echo("Debug is {}".format("on" if ctx.obj["DEBUG"] else "off"))
 
         result = runner.invoke(cli, ["sync"])
         assert result.exception is None
@@ -264,8 +264,8 @@ def test_unprocessed_options(runner):
     @click.argument("args", nargs=-1, type=click.UNPROCESSED)
     @click.option("--verbose", "-v", count=True)
     def cli(verbose, args):
-        click.echo("Verbosity: %s" % verbose)
-        click.echo("Args: %s" % "|".join(args))
+        click.echo("Verbosity: {}".format(verbose))
+        click.echo("Args: {}".format("|".join(args)))
 
     result = runner.invoke(cli, ["-foo", "-vvvvx", "--muhaha", "x", "y", "-x"])
     assert not result.exception
diff --git a/tests/test_context.py b/tests/test_context.py
index 4d131e7..b3a20c6 100644
--- a/tests/test_context.py
+++ b/tests/test_context.py
@@ -90,8 +90,8 @@ def test_get_context_objects_missing(runner):
     assert result.exception is not None
     assert isinstance(result.exception, RuntimeError)
     assert (
-        "Managed to invoke callback without a context object "
-        "of type 'Foo' existing" in str(result.exception)
+        "Managed to invoke callback without a context object of type"
+        " 'Foo' existing" in str(result.exception)
     )
 
 
@@ -129,7 +129,7 @@ def test_global_context_object(runner):
 
 
 def test_context_meta(runner):
-    LANG_KEY = __name__ + ".lang"
+    LANG_KEY = "{}.lang".format(__name__)
 
     def set_language(value):
         click.get_current_context().meta[LANG_KEY] = value
diff --git a/tests/test_defaults.py b/tests/test_defaults.py
index 7b1d7e5..ce44903 100644
--- a/tests/test_defaults.py
+++ b/tests/test_defaults.py
@@ -6,7 +6,7 @@ def test_basic_defaults(runner):
     @click.option("--foo", default=42, type=click.FLOAT)
     def cli(foo):
         assert type(foo) is float
-        click.echo("FOO:[%s]" % foo)
+        click.echo("FOO:[{}]".format(foo))
 
     result = runner.invoke(cli, [])
     assert not result.exception
@@ -23,10 +23,7 @@ def test_multiple_defaults(runner):
 
     result = runner.invoke(cli, [])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "23.0",
-        "42.0",
-    ]
+    assert result.output.splitlines() == ["23.0", "42.0"]
 
 
 def test_nargs_plus_multiple(runner):
@@ -36,11 +33,8 @@ def test_nargs_plus_multiple(runner):
     )
     def cli(arg):
         for item in arg:
-            click.echo("<%d|%d>" % item)
+            click.echo("<{0[0]:d}|{0[1]:d}>".format(item))
 
     result = runner.invoke(cli, [])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "<1|2>",
-        "<3|4>",
-    ]
+    assert result.output.splitlines() == ["<1|2>", "<3|4>"]
diff --git a/tests/test_formatting.py b/tests/test_formatting.py
index 30ab288..4fabbb2 100644
--- a/tests/test_formatting.py
+++ b/tests/test_formatting.py
@@ -151,15 +151,15 @@ def test_formatting_usage_error(runner):
     @click.command()
     @click.argument("arg")
     def cmd(arg):
-        click.echo("arg:" + arg)
+        click.echo("arg:{}".format(arg))
 
     result = runner.invoke(cmd, [])
     assert result.exit_code == 2
     assert result.output.splitlines() == [
         "Usage: cmd [OPTIONS] ARG",
-        'Try "cmd --help" for help.',
+        "Try 'cmd --help' for help.",
         "",
-        'Error: Missing argument "ARG".',
+        "Error: Missing argument 'ARG'.",
     ]
 
 
@@ -178,9 +178,9 @@ def test_formatting_usage_error_metavar_missing_arg(runner):
     assert result.exit_code == 2
     assert result.output.splitlines() == [
         "Usage: cmd [OPTIONS] metavar",
-        'Try "cmd --help" for help.',
+        "Try 'cmd --help' for help.",
         "",
-        'Error: Missing argument "metavar".',
+        "Error: Missing argument 'metavar'.",
     ]
 
 
@@ -194,9 +194,9 @@ def test_formatting_usage_error_metavar_bad_arg(runner):
     assert result.exit_code == 2
     assert result.output.splitlines() == [
         "Usage: cmd [OPTIONS] metavar",
-        'Try "cmd --help" for help.',
+        "Try 'cmd --help' for help.",
         "",
-        'Error: Invalid value for "metavar": 3.14 is not a valid integer',
+        "Error: Invalid value for 'metavar': 3.14 is not a valid integer",
     ]
 
 
@@ -208,15 +208,15 @@ def test_formatting_usage_error_nested(runner):
     @cmd.command()
     @click.argument("bar")
     def foo(bar):
-        click.echo("foo:" + bar)
+        click.echo("foo:{}".format(bar))
 
     result = runner.invoke(cmd, ["foo"])
     assert result.exit_code == 2
     assert result.output.splitlines() == [
         "Usage: cmd foo [OPTIONS] BAR",
-        'Try "cmd foo --help" for help.',
+        "Try 'cmd foo --help' for help.",
         "",
-        'Error: Missing argument "BAR".',
+        "Error: Missing argument 'BAR'.",
     ]
 
 
@@ -224,14 +224,14 @@ def test_formatting_usage_error_no_help(runner):
     @click.command(add_help_option=False)
     @click.argument("arg")
     def cmd(arg):
-        click.echo("arg:" + arg)
+        click.echo("arg:{}".format(arg))
 
     result = runner.invoke(cmd, [])
     assert result.exit_code == 2
     assert result.output.splitlines() == [
         "Usage: cmd [OPTIONS] ARG",
         "",
-        'Error: Missing argument "ARG".',
+        "Error: Missing argument 'ARG'.",
     ]
 
 
@@ -239,15 +239,15 @@ def test_formatting_usage_custom_help(runner):
     @click.command(context_settings=dict(help_option_names=["--man"]))
     @click.argument("arg")
     def cmd(arg):
-        click.echo("arg:" + arg)
+        click.echo("arg:{}".format(arg))
 
     result = runner.invoke(cmd, [])
     assert result.exit_code == 2
     assert result.output.splitlines() == [
         "Usage: cmd [OPTIONS] ARG",
-        'Try "cmd --man" for help.',
+        "Try 'cmd --man' for help.",
         "",
-        'Error: Missing argument "ARG".',
+        "Error: Missing argument 'ARG'.",
     ]
 
 
diff --git a/tests/test_options.py b/tests/test_options.py
index 3974803..4baa374 100644
--- a/tests/test_options.py
+++ b/tests/test_options.py
@@ -47,21 +47,18 @@ def test_nargs_tup_composite_mult(runner):
     @click.option("--item", type=(str, int), multiple=True)
     def copy(item):
         for item in item:
-            click.echo("name=%s id=%d" % item)
+            click.echo("name={0[0]} id={0[1]:d}".format(item))
 
     result = runner.invoke(copy, ["--item", "peter", "1", "--item", "max", "2"])
     assert not result.exception
-    assert result.output.splitlines() == [
-        "name=peter id=1",
-        "name=max id=2",
-    ]
+    assert result.output.splitlines() == ["name=peter id=1", "name=max id=2"]
 
 
 def test_counting(runner):
     @click.command()
     @click.option("-v", count=True, help="Verbosity", type=click.IntRange(0, 3))
     def cli(v):
-        click.echo("verbosity=%d" % v)
+        click.echo("verbosity={:d}".format(v))
 
     result = runner.invoke(cli, ["-vvv"])
     assert not result.exception
@@ -70,7 +67,7 @@ def test_counting(runner):
     result = runner.invoke(cli, ["-vvvv"])
     assert result.exception
     assert (
-        'Invalid value for "-v": 4 is not in the valid range of 0 to 3.'
+        "Invalid value for '-v': 4 is not in the valid range of 0 to 3."
         in result.output
     )
 
@@ -105,14 +102,14 @@ def test_multiple_required(runner):
 
     result = runner.invoke(cli, [])
     assert result.exception
-    assert 'Error: Missing option "-m" / "--message".' in result.output
+    assert "Error: Missing option '-m' / '--message'." in result.output
 
 
 def test_empty_envvar(runner):
     @click.command()
     @click.option("--mypath", type=click.Path(exists=True), envvar="MYPATH")
     def cli(mypath):
-        click.echo("mypath: %s" % mypath)
+        click.echo("mypath: {}".format(mypath))
 
     result = runner.invoke(cli, [], env={"MYPATH": ""})
     assert result.exit_code == 0
@@ -149,7 +146,7 @@ def test_multiple_envvar(runner):
         cmd,
         [],
         auto_envvar_prefix="TEST",
-        env={"TEST_ARG": "foo%sbar" % os.path.pathsep},
+        env={"TEST_ARG": "foo{}bar".format(os.path.pathsep)},
     )
     assert not result.exception
     assert result.output == "foo|bar\n"
@@ -306,7 +303,7 @@ def test_custom_validation(runner):
         click.echo(foo)
 
     result = runner.invoke(cmd, ["--foo", "-1"])
-    assert 'Invalid value for "--foo": Value needs to be positive' in result.output
+    assert "Invalid value for '--foo': Value needs to be positive" in result.output
 
     result = runner.invoke(cmd, ["--foo", "42"])
     assert result.output == "42\n"
@@ -359,7 +356,7 @@ def test_missing_choice(runner):
     result = runner.invoke(cmd)
     assert result.exit_code == 2
     error, separator, choices = result.output.partition("Choose from")
-    assert 'Error: Missing option "--foo". ' in error
+    assert "Error: Missing option '--foo'. " in error
     assert "Choose from" in separator
     assert "foo" in choices
     assert "bar" in choices
diff --git a/tests/test_testing.py b/tests/test_testing.py
index f2d2d9a..22a285d 100644
--- a/tests/test_testing.py
+++ b/tests/test_testing.py
@@ -65,7 +65,7 @@ def test_prompts():
     @click.command()
     @click.option("--foo", prompt=True)
     def test(foo):
-        click.echo("foo=%s" % foo)
+        click.echo("foo={}".format(foo))
 
     runner = CliRunner()
     result = runner.invoke(test, input="wau wau\n")
@@ -75,7 +75,7 @@ def test_prompts():
     @click.command()
     @click.option("--foo", prompt=True, hide_input=True)
     def test(foo):
-        click.echo("foo=%s" % foo)
+        click.echo("foo={}".format(foo))
 
     runner = CliRunner()
     result = runner.invoke(test, input="wau wau\n")
@@ -131,7 +131,7 @@ def test_with_color():
     assert not result.exception
 
     result = runner.invoke(cli, color=True)
-    assert result.output == click.style("hello world", fg="blue") + "\n"
+    assert result.output == "{}\n".format(click.style("hello world", fg="blue"))
     assert not result.exception
 
 
@@ -219,7 +219,7 @@ def test_exit_code_and_output_from_sys_exit():
 def test_env():
     @click.command()
     def cli_env():
-        click.echo("ENV=%s" % os.environ["TEST_CLICK_ENV"])
+        click.echo("ENV={}".format(os.environ["TEST_CLICK_ENV"]))
 
     runner = CliRunner()
 
diff --git a/tests/test_utils.py b/tests/test_utils.py
index 5247224..d86f59b 100644
--- a/tests/test_utils.py
+++ b/tests/test_utils.py
@@ -203,21 +203,21 @@ def test_echo_color_flag(monkeypatch, capfd):
 
     click.echo(styled_text, color=False)
     out, err = capfd.readouterr()
-    assert out == text + "\n"
+    assert out == "{}\n".format(text)
 
     click.echo(styled_text, color=True)
     out, err = capfd.readouterr()
-    assert out == styled_text + "\n"
+    assert out == "{}\n".format(styled_text)
 
     isatty = True
     click.echo(styled_text)
     out, err = capfd.readouterr()
-    assert out == styled_text + "\n"
+    assert out == "{}\n".format(styled_text)
 
     isatty = False
     click.echo(styled_text)
     out, err = capfd.readouterr()
-    assert out == text + "\n"
+    assert out == "{}\n".format(text)
 
 
 @pytest.mark.skipif(WIN, reason="Test too complex to make work windows.")