Unifying "do X on save" functionality

Problem VS Code ships with multiple actions that can be triggered on save, including:

• Trim trailing whitespace
• Trim trailing new line
• format document
• code actions (such as organize imports and fix all)

Each of these actions currently has its own setting. Many of the setting names are generic so it may not be clear they apply on save.

Goals

• Make it easier to discover built-in do X on save actions
• Give these settings a more consistent names
• Potentially allow these actions to be used in a more flexible way (such as from the source action menu)

/cc @kieferrm

[mjbvz]

Sketch 3 — Add a new setting

Add a new editor.onSave setting that unifies all of these. This setting would be an array of actions that are run in order:

    "editor.onSave": [
        "format",
        { "codeAction": "bla" },
        "files.trimFinalNewlines"
    ]

Pros

• Clean
• single setting

Cons

• Discoverability
• We’d need to figure out how this new setting plays with all the existing settings

[mjbvz]

Sketch 1 — Everything is a source Action

Convert all on save actions into source code actions. Use the single editor.codeActionsOnSave setting to enable or disable individual actions:

"editor.codeActionsOnSave": {
      "source.organizeImports": true,
      "source.format": true,
      "source.trimTrailingNewLines": true,
}

Pros

• Single setting `editor.codeActionsOnSave``
• You can easily create keybindings for source actions
• They would show up in the source context menu.

Cons

• Order that actions are run in becomes less clear. With our current implementation, we always run code actions and then format for example
• Creating some code actions, such as format actions, may be expensive.