Files
docker-cli/cli/command/image/save_test.go
Sebastiaan van Stijn ab230240ad 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>
2024-07-04 01:35:12 +02:00

116 lines
3.2 KiB
Go

package image
import (
"io"
"os"
"strings"
"testing"
"github.com/docker/cli/internal/test"
"github.com/pkg/errors"
"gotest.tools/v3/assert"
is "gotest.tools/v3/assert/cmp"
)
func TestNewSaveCommandErrors(t *testing.T) {
testCases := []struct {
name string
args []string
isTerminal bool
expectedError string
imageSaveFunc func(images []string) (io.ReadCloser, error)
}{
{
name: "wrong args",
args: []string{},
expectedError: "requires at least 1 argument.",
},
{
name: "output to terminal",
args: []string{"output", "file", "arg1"},
isTerminal: true,
expectedError: "cowardly refusing to save to a terminal. Use the -o flag or redirect",
},
{
name: "ImageSave fail",
args: []string{"arg1"},
isTerminal: false,
expectedError: "error saving image",
imageSaveFunc: func(images []string) (io.ReadCloser, error) {
return io.NopCloser(strings.NewReader("")), errors.Errorf("error saving image")
},
},
{
name: "output directory does not exist",
args: []string{"-o", "fakedir/out.tar", "arg1"},
expectedError: "failed to save image: invalid output path: directory \"fakedir\" does not exist",
},
{
name: "output file is irregular",
args: []string{"-o", "/dev/null", "arg1"},
expectedError: "failed to save image: invalid output path: \"/dev/null\" must be a directory or a regular file",
},
}
for _, tc := range testCases {
tc := tc
t.Run(tc.name, func(t *testing.T) {
cli := test.NewFakeCli(&fakeClient{imageSaveFunc: tc.imageSaveFunc})
cli.Out().SetIsTerminal(tc.isTerminal)
cmd := NewSaveCommand(cli)
cmd.SetOut(io.Discard)
cmd.SetErr(io.Discard)
cmd.SetArgs(tc.args)
assert.ErrorContains(t, cmd.Execute(), tc.expectedError)
})
}
}
func TestNewSaveCommandSuccess(t *testing.T) {
testCases := []struct {
args []string
isTerminal bool
imageSaveFunc func(images []string) (io.ReadCloser, error)
deferredFunc func()
}{
{
args: []string{"-o", "save_tmp_file", "arg1"},
isTerminal: true,
imageSaveFunc: func(images []string) (io.ReadCloser, error) {
assert.Assert(t, is.Len(images, 1))
assert.Check(t, is.Equal("arg1", images[0]))
return io.NopCloser(strings.NewReader("")), nil
},
deferredFunc: func() {
_ = os.Remove("save_tmp_file")
},
},
{
args: []string{"arg1", "arg2"},
isTerminal: false,
imageSaveFunc: func(images []string) (io.ReadCloser, error) {
assert.Assert(t, is.Len(images, 2))
assert.Check(t, is.Equal("arg1", images[0]))
assert.Check(t, is.Equal("arg2", images[1]))
return io.NopCloser(strings.NewReader("")), nil
},
},
}
for _, tc := range testCases {
tc := tc
t.Run(strings.Join(tc.args, " "), func(t *testing.T) {
cmd := NewSaveCommand(test.NewFakeCli(&fakeClient{
imageSaveFunc: func(images []string) (io.ReadCloser, error) {
return io.NopCloser(strings.NewReader("")), nil
},
}))
cmd.SetOut(io.Discard)
cmd.SetErr(io.Discard)
cmd.SetArgs(tc.args)
assert.NilError(t, cmd.Execute())
if tc.deferredFunc != nil {
tc.deferredFunc()
}
})
}
}