Override config file option value with option parameter

[VonC]

The "Features with examples" sections includes:

Default values from a JSON config file, unmarshalled via your config struct

It refers to eg-config, which shows the program returns the config file default value, even when the command-line option specifies a different value.

$ config --bar moon
hello
world

Is this a bug or a feature?

If I store a static value 'world' for bar in config.json, but want to override it for this one-time execution on the command line, with --bar moon, I expect to see moon, not world.

I only expect to see world if I don't specify any option, which means the value of bar should be its default one, read from the config.json file.

Do I interpret that incorrectly?
Should I expect to override on command-line, with options, a default value read from a configuration file?

[jpillora]

This is a bug This was complicated by the fact the path to the configuration file can a flag. So to fix this, we need to parse flags over a dummy struct, config file flag? Then parse config over real struct , then parse flags over real struct

…

On Mon, 28 Oct 2019 at 6:54 pm VonC ***@***.***> wrote: The "Features with examples <https://github.com/jpillora/opts/blob/8ed9e9c54b865d3d47b939b24b672a1355cd375a/README.md#features-with-examples>" sections includes: Default values from a JSON config file, unmarshalled via your config struct It refers to eg-config <https://github.com/jpillora/opts-examples/tree/559c3c9618b03835f19897973946c1afa775f2d0/eg-config>, which shows the program returns the config file *default* value, *even when the command-line option specifies a different value*. $ config --bar moon hello world Is this a bug or a feature? If I store a static value 'world' for bar in config.json, but want to override it for this one-time execution on the command line, with --bar moon, I expect to see moon, not world. I only expect to see world if I don't specify any option, which means the value of bar should be its *default* one, read from the config.json file. Do I interpret that incorrectly? Should I expect to override on command-line, with options, a *default* value read from a configuration file? — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#25?email_source=notifications&email_token=AAE2X462JP6JVMJZ5PDUUPDQQ2LDBA5CNFSM4JFWUZ4KYY3PNVWWK3TUL52HS4DFUVEXG43VMWVGG33NNVSW45C7NFSM4HUWAZ5Q>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AAE2X46E77W7SK4XG5DTKTDQQ2LDBANCNFSM4JFWUZ4A> .

[VonC]

@jpillora OK, I thought I was using opts incorrectly ;-)

I'll have a look at the code then.

In the meantime, I found the "workaround" of:

• redeclaring my Config fields as regular go flags
• parsing those flags
• overriding the config.value if said flags are valued

Not very convenient, but it works.

[VonC]

@jpillora By any chance, did you review my proposed fix for this bug, with #26?

It does work quite well.