Inconsistent behavior on invalid config

[arvigeus]

.markdownlint.json

{
  "extends": "this-file-does-not-exist.json"
}

Running markdownlint --fix '**/*.md' silently fails to load invalid file and goes to default config.

Running markdownlint --fix '**/*.md' --config .markdownlint.json displays an error message that this-file-does-not-exist.json is missing.

In my case I was trying to load a valid file that was missing, and it took me some time to realize that the problem is me, not markdownlint being lazy not loading .markdownlint.json. I think it should complain in this case, instead of straight up loading default config.

[victoriadrake]

Continuation of: a1f9a15#r40919702

I also experienced markdownlint (markdownlint-cli) silently using a default config when I had it run as a pre-commit hook (pre-commit framework). I had passed in a non-existent file path to --config by mistake. Here’s what the hook looks like in .pre-commit-config.yaml:

  - repo: local
    hooks:
      - id: markdownlint
        name: markdownlint
        description: "Lint Markdown files"
        entry: markdownlint '**/*.md' --fix --ignore node_modules --config "./.markdownlint.json"
        language: node
        types: [markdown]

In this scenario, .markdownlint.json did not exist in the project root. I had also tried it with a YAML formatted config file before realizing the erroneous file path.

Expected behavior: an error is raised when the config file does not exist, ie:

Config file not found. Using default config...

[janosh]

@DavidAnson As a fix, do you prefer a custom error message or just bubble up whatever error is thrown when one of these lines fails?

      const userConfig = jsConfigFile ?
        // Evaluate .js configuration file as code
        require(path.resolve(processCwd, userConfigFile)) :
        // Load JSON/YAML configuration as data
        markdownlint.readConfigSync(userConfigFile, configFileParsers);
      config = require('deep-extend')(config, userConfig);

[DavidAnson]

Both? ;) A general message is good for context while the specific error is good for details. Something like "Error reading configuration file: " + exception.message.