this repo has no description
cmd/cue: add -C flag, like `go` and `git`
cmd/cue gains a -C flag that changes the working directory before any
other processing. -C must be the first argument and accepts either
"-C dir" or "-C=dir". This mirrors the flag added to cmd/go in
https://go.dev/cl/421436, and follows the same constraint that -C must
precede the subcommand.
Note that other tools like `git` allow the -C flag to come after other
flags even though it affects all flags, and even multiple -C flags.
We don't support these for now as they seem unnecessary.
Fixes #1918
Signed-off-by: Daniel Martí <mvdan@mvdan.cc>
Change-Id: I4ee255d08ea507bd771481af6932b0ebb34e3b6b
Reviewed-on: https://cue.gerrithub.io/c/cue-lang/cue/+/1236314
Reviewed-by: Paul Jolly <paul@myitcv.io>
TryBot-Result: CUEcueckoo <cueckoo@cuelang.org>
+117
-9
+2
cmd/cue/cmd/flags.go
+2
cmd/cue/cmd/flags.go
···
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flagAllErrors flagName = "all-errors"
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flagAllMajor flagName = "all-major"
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flagAllVersions flagName = "all-versions"
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flagChdir flagName = "chdir"
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flagCheck flagName = "check"
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flagDeps flagName = "deps"
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flagDiff flagName = "diff"
···
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f.BoolP(string(flagIgnore), "i", false,
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"proceed in the presence of errors")
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f.BoolP(string(flagAllErrors), "E", false, "print all available errors")
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f.VarP(chdirFlag{}, string(flagChdir), "C", "change working directory before running command (must be the first flag)")
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f.String(string(flagCpuProfile), "", "write a CPU profile to the specified file before exiting")
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f.MarkHidden(string(flagCpuProfile))
+51
cmd/cue/cmd/root.go
+51
cmd/cue/cmd/root.go
···
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"os"
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"runtime"
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"runtime/pprof"
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"strings"
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"sync"
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"testing"
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"time"
···
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// The API could also be made clearer if we want to keep cmd public,
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// such as not leaking *cobra.Command via embedding.
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// handleChdirFlag consumes a leading -C flag from args, if any, and changes
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// the working directory accordingly. The flag must be the first argument, in
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// one of the forms "-C dir", "-C=dir", "--chdir dir", or "--chdir=dir". Modeled
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// on cmd/go's handling of -C; see https://go.dev/cl/421436.
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//
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// Any -C left in args is rejected later by cobra via [chdirFlag.Set], which
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// covers both repeated -C flags and -C following another flag.
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func handleChdirFlag(args []string) ([]string, error) {
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if len(args) == 0 {
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return args, nil
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}
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a := args[0]
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var dir string
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switch {
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case a == "-C" || a == "--chdir":
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if len(args) < 2 {
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// Let cobra report the missing argument.
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return args, nil
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}
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dir = args[1]
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args = args[2:]
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case strings.HasPrefix(a, "-C=") || strings.HasPrefix(a, "--chdir="):
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_, dir, _ = strings.Cut(a, "=")
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args = args[1:]
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default:
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return args, nil
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}
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if err := os.Chdir(dir); err != nil {
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return args, err
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}
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return args, nil
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}
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// chdirFlag is a [pflag.Value] that always rejects assignment. The actual -C
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// handling happens in [handleChdirFlag] before cobra parses; cobra only sees
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// -C if it appears after another argument or is repeated, both of which are
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// errors.
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type chdirFlag struct{}
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func (chdirFlag) String() string { return "" }
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func (chdirFlag) Type() string { return "string" }
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func (chdirFlag) Set(string) error {
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return fmt.Errorf("must be the first argument")
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}
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// New creates the top-level command.
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// The returned error is always nil, and is a historical artifact.
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func New(args []string) (*Command, error) {
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args, err := handleChdirFlag(args)
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if err != nil {
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fmt.Fprintf(os.Stderr, "%v\n", err)
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os.Exit(1)
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}
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// Each call to New resets rootWorkingDir, to support [os.Chdir] calls in between.
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rootWorkingDir = sync.OnceValue(func() string {
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wd, err := os.Getwd()
+52
cmd/cue/cmd/testdata/script/chdir.txtar
+52
cmd/cue/cmd/testdata/script/chdir.txtar
···
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# Verify that the top-level -C flag changes the working directory before
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# running the requested subcommand. Mirrors the behavior of cmd/go's -C flag.
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exec cue -C sub export
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cmp stdout expect-stdout
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exec cue -C=sub export
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cmp stdout expect-stdout
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exec cue --chdir sub export
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cmp stdout expect-stdout
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# -C must be the first argument; placing it after a subcommand fails.
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! exec cue export -C sub
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cmp stderr stderr-not-first
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# -C must come before any other global flag, too.
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# Note that the "invalid argument" part of the error is unfortunate,
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# but avoiding that with cobra and pflag is cumbersome.
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! exec cue -E -C sub export
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cmp stderr stderr-not-first
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# -C may only be given once.
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! exec cue -C sub -C nested export
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cmp stderr stderr-repeated
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# -C must be followed by an argument.
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! exec cue -C
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cmp stderr stderr-missing-arg
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# -C must point to an existing directory.
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# Note that the underlying OS error message varies on Windows.
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! exec cue -C nonexistent export
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[unix] cmp stderr stderr-bad-dir-unix
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[windows] stderr 'chdir nonexistent:'
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-- expect-stdout --
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{
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"foo": 42
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}
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-- stderr-not-first --
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invalid argument "sub" for "-C, --chdir" flag: must be the first argument
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-- stderr-repeated --
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invalid argument "nested" for "-C, --chdir" flag: must be the first argument
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-- stderr-missing-arg --
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flag needs an argument: 'C' in -C
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-- stderr-bad-dir-unix --
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chdir nonexistent: no such file or directory
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-- sub/x.cue --
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package x
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foo: 42
+8
-6
cmd/cue/cmd/testdata/script/help_cmd.txtar
+8
-6
cmd/cue/cmd/testdata/script/help_cmd.txtar
···
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-T, --inject-vars inject system variables in tags (default true)
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Global Flags:
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-E, --all-errors print all available errors
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-i, --ignore proceed in the presence of errors
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-s, --simplify simplify output
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-E, --all-errors print all available errors
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-C, --chdir string change working directory before running command (must be the first flag)
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-i, --ignore proceed in the presence of errors
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-s, --simplify simplify output
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Use "cue cmd [command] --help" for more information about a command.
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-- cue-help-cmd-hello.stdout --
···
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cue cmd hello [flags]
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Global Flags:
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-E, --all-errors print all available errors
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-i, --ignore proceed in the presence of errors
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-s, --simplify simplify output
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-E, --all-errors print all available errors
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-C, --chdir string change working directory before running command (must be the first flag)
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-i, --ignore proceed in the presence of errors
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-s, --simplify simplify output
+4
-3
cmd/cue/cmd/testdata/script/help_cmd_flags.txtar
+4
-3
cmd/cue/cmd/testdata/script/help_cmd_flags.txtar
···
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-T, --inject-vars inject system variables in tags (default true)
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Global Flags:
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-
-E, --all-errors print all available errors
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-
-i, --ignore proceed in the presence of errors
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-
-s, --simplify simplify output
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+
-E, --all-errors print all available errors
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+
-C, --chdir string change working directory before running command (must be the first flag)
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+
-i, --ignore proceed in the presence of errors
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+
-s, --simplify simplify output