test spring-cleaning

This makes a quick pass through our tests;

Discard output/err
----------------------------------------------

Many tests were testing for error-conditions, but didn't discard output.
This produced a lot of noise when running the tests, and made it hard
to discover if there were actual failures, or if the output was expected.
For example:

    === RUN   TestConfigCreateErrors
    Error: "create" requires exactly 2 arguments.
    See 'create --help'.

    Usage:  create [OPTIONS] CONFIG file|- [flags]

    Create a config from a file or STDIN
    Error: "create" requires exactly 2 arguments.
    See 'create --help'.

    Usage:  create [OPTIONS] CONFIG file|- [flags]

    Create a config from a file or STDIN
    Error: error creating config
    --- PASS: TestConfigCreateErrors (0.00s)

And after discarding output:

    === RUN   TestConfigCreateErrors
    --- PASS: TestConfigCreateErrors (0.00s)

Use sub-tests where possible
----------------------------------------------

Some tests were already set-up to use test-tables, and even had a usable
name (or in some cases "error" to check for). Change them to actual sub-
tests. Same test as above, but now with sub-tests and output discarded:

    === RUN   TestConfigCreateErrors
    === RUN   TestConfigCreateErrors/requires_exactly_2_arguments
    === RUN   TestConfigCreateErrors/requires_exactly_2_arguments#01
    === RUN   TestConfigCreateErrors/error_creating_config
    --- PASS: TestConfigCreateErrors (0.00s)
        --- PASS: TestConfigCreateErrors/requires_exactly_2_arguments (0.00s)
        --- PASS: TestConfigCreateErrors/requires_exactly_2_arguments#01 (0.00s)
        --- PASS: TestConfigCreateErrors/error_creating_config (0.00s)
    PASS

It's not perfect in all cases (in the above, there's duplicate "expected"
errors, but Go conveniently adds "#01" for the duplicate). There's probably
also various tests I missed that could still use the same changes applied;
we can improve these in follow-ups.

Set cmd.Args to prevent test-failures
----------------------------------------------

When running tests from my IDE, it compiles the tests before running,
then executes the compiled binary to run the tests. Cobra doesn't like
that, because in that situation `os.Args` is taken as argument for the
command that's executed. The command that's tested now sees the test-
flags as arguments (`-test.v -test.run ..`), which causes various tests
to fail ("Command XYZ does not accept arguments").

    # compile the tests:
    go test -c -o foo.test

    # execute the test:
    ./foo.test -test.v -test.run TestFoo
    === RUN   TestFoo
    Error: "foo" accepts no arguments.

The Cobra maintainers ran into the same situation, and for their own
use have added a special case to ignore `os.Args` in these cases;
https://github.com/spf13/cobra/blob/v1.8.1/command.go#L1078-L1083

    args := c.args

    // Workaround FAIL with "go test -v" or "cobra.test -test.v", see #155
    if c.args == nil && filepath.Base(os.Args[0]) != "cobra.test" {
        args = os.Args[1:]
    }

Unfortunately, that exception is too specific (only checks for `cobra.test`),
so doesn't automatically fix the issue for other test-binaries. They did
provide a `cmd.SetArgs()` utility for this purpose
https://github.com/spf13/cobra/blob/v1.8.1/command.go#L276-L280

    // SetArgs sets arguments for the command. It is set to os.Args[1:] by default, if desired, can be overridden
    // particularly useful when testing.
    func (c *Command) SetArgs(a []string) {
        c.args = a
    }

And the fix is to explicitly set the command's args to an empty slice to
prevent Cobra from falling back to using `os.Args[1:]` as arguments.

    cmd := newSomeThingCommand()
    cmd.SetArgs([]string{})

Some tests already take this issue into account, and I updated some tests
for this, but there's likely many other ones that can use the same treatment.

Perhaps the Cobra maintainers would accept a contribution to make their
condition less specific and to look for binaries ending with a `.test`
suffix (which is what compiled binaries usually are named as).

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

cli/command/stack/config_test.go

@@ -13,6 +13,7 @@ import (
 func TestConfigWithEmptyComposeFile(t *testing.T) {
 	cmd := newConfigCommand(test.NewFakeCli(&fakeClient{}))
 	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
 
 	assert.ErrorContains(t, cmd.Execute(), `Specify a Compose file`)
 }

cli/command/stack/deploy_test.go

@@ -12,6 +12,7 @@ func TestDeployWithEmptyName(t *testing.T) {
 	cmd := newDeployCommand(test.NewFakeCli(&fakeClient{}))
 	cmd.SetArgs([]string{"'   '"})
 	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
 
 	assert.ErrorContains(t, cmd.Execute(), `invalid stack name: "'   '"`)
 }

cli/command/stack/list_test.go

@@ -25,18 +25,21 @@ func TestListErrors(t *testing.T) {
 			expectedError: "accepts no argument",
 		},
 		{
+			args: []string{},
 			flags: map[string]string{
 				"format": "{{invalid format}}",
 			},
 			expectedError: "template parsing error",
 		},
 		{
+			args: []string{},
 			serviceListFunc: func(options types.ServiceListOptions) ([]swarm.Service, error) {
 				return []swarm.Service{}, errors.Errorf("error getting services")
 			},
 			expectedError: "error getting services",
 		},
 		{
+			args: []string{},
 			serviceListFunc: func(options types.ServiceListOptions) ([]swarm.Service, error) {
 				return []swarm.Service{*builders.Service()}, nil
 			},
@@ -45,15 +48,19 @@ func TestListErrors(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
-		cmd := newListCommand(test.NewFakeCli(&fakeClient{
-			serviceListFunc: tc.serviceListFunc,
-		}))
-		cmd.SetArgs(tc.args)
-		cmd.SetOut(io.Discard)
-		for key, value := range tc.flags {
-			assert.Check(t, cmd.Flags().Set(key, value))
-		}
-		assert.ErrorContains(t, cmd.Execute(), tc.expectedError)
+		tc := tc
+		t.Run(tc.expectedError, func(t *testing.T) {
+			cmd := newListCommand(test.NewFakeCli(&fakeClient{
+				serviceListFunc: tc.serviceListFunc,
+			}))
+			cmd.SetArgs(tc.args)
+			cmd.SetOut(io.Discard)
+			cmd.SetErr(io.Discard)
+			for key, value := range tc.flags {
+				assert.Check(t, cmd.Flags().Set(key, value))
+			}
+			assert.ErrorContains(t, cmd.Execute(), tc.expectedError)
+		})
 	}
 }
 
@@ -97,6 +104,7 @@ func TestStackList(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
+		tc := tc
 		t.Run(tc.doc, func(t *testing.T) {
 			var services []swarm.Service
 			for _, name := range tc.serviceNames {

cli/command/stack/ps_test.go

@@ -40,12 +40,16 @@ func TestStackPsErrors(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
-		cmd := newPsCommand(test.NewFakeCli(&fakeClient{
-			taskListFunc: tc.taskListFunc,
-		}))
-		cmd.SetArgs(tc.args)
-		cmd.SetOut(io.Discard)
-		assert.ErrorContains(t, cmd.Execute(), tc.expectedError)
+		tc := tc
+		t.Run(tc.expectedError, func(t *testing.T) {
+			cmd := newPsCommand(test.NewFakeCli(&fakeClient{
+				taskListFunc: tc.taskListFunc,
+			}))
+			cmd.SetArgs(tc.args)
+			cmd.SetOut(io.Discard)
+			cmd.SetErr(io.Discard)
+			assert.ErrorContains(t, cmd.Execute(), tc.expectedError)
+		})
 	}
 }
 
@@ -156,6 +160,7 @@ func TestStackPs(t *testing.T) {
 	}
 
 	for _, tc := range testCases {
+		tc := tc
 		t.Run(tc.doc, func(t *testing.T) {
 			cli := test.NewFakeCli(&fakeClient{
 				taskListFunc:       tc.taskListFunc,
@@ -169,6 +174,7 @@ func TestStackPs(t *testing.T) {
 				assert.Check(t, cmd.Flags().Set(key, value))
 			}
 			cmd.SetOut(io.Discard)
+			cmd.SetErr(io.Discard)
 
 			if tc.expectedErr != "" {
 				assert.Error(t, cmd.Execute(), tc.expectedErr)

cli/command/stack/remove_test.go

@@ -45,6 +45,7 @@ func TestRemoveWithEmptyName(t *testing.T) {
 	cmd := newRemoveCommand(test.NewFakeCli(&fakeClient{}))
 	cmd.SetArgs([]string{"good", "'   '", "alsogood"})
 	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
 
 	assert.ErrorContains(t, cmd.Execute(), `invalid stack name: "'   '"`)
 }
@@ -157,6 +158,7 @@ func TestRemoveContinueAfterError(t *testing.T) {
 	}
 	cmd := newRemoveCommand(test.NewFakeCli(cli))
 	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
 	cmd.SetArgs([]string{"foo", "bar"})
 
 	assert.Error(t, cmd.Execute(), "Failed to remove some resources from stack: foo")

cli/command/stack/services_test.go

@@ -80,6 +80,7 @@ func TestStackServicesErrors(t *testing.T) {
 				assert.Check(t, cmd.Flags().Set(key, value))
 			}
 			cmd.SetOut(io.Discard)
+			cmd.SetErr(io.Discard)
 			assert.ErrorContains(t, cmd.Execute(), tc.expectedError)
 		})
 	}
@@ -89,6 +90,7 @@ func TestRunServicesWithEmptyName(t *testing.T) {
 	cmd := newServicesCommand(test.NewFakeCli(&fakeClient{}))
 	cmd.SetArgs([]string{"'   '"})
 	cmd.SetOut(io.Discard)
+	cmd.SetErr(io.Discard)
 
 	assert.ErrorContains(t, cmd.Execute(), `invalid stack name: "'   '"`)
 }