fix: per-command config

[reggi]

Command-Specific Flags Implementation Checklist

This PR enables commands to define their own distinct flags separate from global configuration, eliminating the need for verbose prefixed flags like --init-name and allowing cleaner command-specific options.

Key Features

• New flags configuration source - Adds a dedicated layer in the config hierarchy for command-specific flags without modifying existing sources
• Command definition merging - Implements loadCommand() method to merge command-specific definitions with global definitions
• Warning deduplication - Captures and deduplicates warnings during initial config load to prevent duplicate messages across sources
• Synchronous design - No new async calls or config instances, integrates seamlessly with existing load flow
• Clean flag naming - Enables commands to use simple flags (e.g., --name) instead of verbose prefixed versions (e.g., --init-name)

Implementation Tasks

• Add flags to config source hierarchy (between env and cli)
• Implement loadCommand(definitions) method for dynamic definition merging
• Add warning capture system (#warnings array) to delay logging until after command load
• Implement removeWarnings(types) to clear superseded warnings
• Implement #deduplicateWarnings() to prevent duplicate warnings
• Add logWarnings() method to flush captured warnings
• Update type/default merging to support command-specific definitions
• Handle exclusive flag validation across merged definitions
• Update checkUnknown() to recognize both cli and flags sources
• Test command-specific flag parsing and precedence

[reggi]

Now just running npm run prepack will make sure all commands have a .md file and add it to nav.yml and generate a md with flags populated example below:

  ---
  title: npm-tset
  section: 1
  description: A test command with custom flags
  ---

  ### Synopsis

  ```bash
  npm tset [options]
  ```

  Note: This command is unaware of workspaces.

  ### Description

  A test command with custom flags

  ### Configuration

  #### `say`

  * Default: "hello"
  * Type: String

  What to say when running the test command



  ### See Also

  * [npm help config](/commands/npm-config)

[ljharb]

yay! (seems more like a feat than a chore tho :-p)

so does this mean i'll be able to set a top-level config value, but then override it for a specific command?

[reggi]

@ljharb

yay! (seems more like a feat than a chore tho :-p)

so does this mean i'll be able to set a top-level config value, but then override it for a specific command?

I put it as a chore because It's not really a customer facing thing. It just allows commands to not need to have prefix flags like what init did with --init-name and we can just do --name...

[wraithgar]

It has to be at least a fix since it affects the published code. chore is reserved for things that shouldn't trigger a new published version.

[wraithgar]

so does this mean i'll be able to set a top-level config value, but then override it for a specific command?

No it means we can define a config that only is for a specific command. Obviously these couldn't go into config files (yet?). This will allow commands to have overlapping names in config that have wholly separate configs (i.e. --name in npm init could have different rules than --name in npm token create)

[ljharb]

ah ok, gotcha. i'm not sure how name in npmrc would work tho in that example, if there's two distinct sets of possible values for that config key?

meaning, merely adding a command line config whose acceptable values differ across commands would make that config name poisoned (in npmrc or env vars) until the capability exists for users to override a config value more granularly down to a specific command

[reggi]

@ljharb this PR adds command-level configs just for flags (no .npmrc support, and that's intentional) for new commands. If / when we want that we could go with ini "sections" syntax like this:

[command-foo]
name=hello world

[command-bar]
name=true

[ljharb]

right - but as soon as you add that example without npmrc/env var support, the string "name" in npmrc becomes broken. Meaning, it's not just about new commands, it's that adding any new config key becomes a breaking change, because someone could have it in their env or npmrc.