Extract snippet from file `refactor.extract` CodeAction

[charlespwd]

The LSP defines some CodeActionKinds that have special meanings in some Language Clients. One of those is the RefactorExtract action kind.

We could probably offer a RefactorExtract action when you highlight a large range of text inside a section|template|snippet.

When executed, we could do something like this:

• For range Y in input file X:
  1. Find all non-global variables in Y
  2. Create a file snippets/Z.liquid with the contents of Y
  3. Replace Y in X by the following:

    {%
      render '#{Z}',
      #{all_the_non_global_variables_as_arguments}
    %}
  

To be answered:

• Can we prompt for a filename during that process?

Resources

1. https://microsoft.github.io/language-server-protocol/specifications/specification-3-17/#textDocument_codeAction

[charlespwd]

Partially depends on #412 .

Having to manually rename newFile is kind of gross.

[charlespwd]

Sketching out the flow

sequenceDiagram
    actor A as User
    participant C as Client
    participant S as Server
    A-->>C: Select code and right click
    C->>+S: "textDocument/codeAction" request,<br>context.triggerKind: "invoked"
    S->>-C: CodeAction[]<br>kind: "refactor.extract"<br>command: "shopifyLiquid/extractSnippet"<br>args: uri, range
    C-->>A: Show options
    A-->>C: Select "Extract to new file"
    C->>S: "workspace/executeCommand" request<br>command: "shopify/extractSnippet"<br>args: uri, range
    activate S
    S->>S: Compute WorkspaceEdit for refactor
    S->>C: "workspace/applyEdit" request
    activate C
    C->>S: applied!
    deactivate C
    S->>C: done!
    deactivate S

Therefore here are the things I need to build:

• A CodeAction provider of kind "refactor.extract"
• A ExecuteCommand provider for "shopify/extractSnippet" commands

[aswamy]

would “Select to refactor into a new file” be possible to take a “Section block” and move it to a /blocks/_blockName.liquid file, and then update the schema for that section to now accept that block?

-Ben

[charlespwd]

@aswamy @benjaminsehl, yes we def could add a different refactor.extract code action for this.