CLI/Watch - Extract with [files] marks other strings as obsolete in messages file

Describe the bug I am in the middle of writing a little script to automate extraction of strings using chockidar as watcher.

Unfortunately I have came across 2 errors.

1. CLI - Whenever I pass a [files] string into the cmd it is not recognized and command is extracting from all source path provided in config file of lingui. But for my case it is not really important, just pointing this out. Ex. command lingui extract src/pages/SignIn/SignIn.tsx --verbose.
2. Main problem - after hitting the default function of @lingui/cli/lingui-extract with a linguiConfig and linguiOptions prepared based on the source code I have managed to get the “cli” to extract from the file I pin-pointed, BUT after the extraction all other previously extracted strings from other files are marked as obsolete.

To Reproduce Just run this code via npm. It is just a base code to run the extraction from script.

const { getConfig, LinguiConfig } = require('@lingui/conf');

const linguiExtract = require('../node_modules/@lingui/cli/lingui-extract').default;

const linguiConfig = getConfig({
  configPath: process.env.LINGUI_CONFIG,
});

const linguiOptions = {
  verbose: true,
  clean: false,
  overwrite: true,
  files: ['src/pages/SignIn/SignIn.tsx'],
};

function prepareLinguiExtract(config, options) {
  linguiExtract(config, options);
}

prepareLinguiExtract(linguiConfig, linguiOptions);

Expected behavior I expect it to just extract string from the file I am pointing to, not to modify the whole messages file.

Additional context

• jsLingui version 3.4.0
• Babel version 7.12.3
• CRA ejected, React 17.0.1

[jack1913]

Sure, I can work on this. I already have a working code I can implement it natively, but I will sit to it by the end of the week.

[semoal]

Released your funcitonality with 3.6.0. Thanks for the contribution!