deno fmt <path> in a workspace applies members' options to wrong paths

[0x009922]

Version: Deno 2.2.5

Steps to reproduce

Create the following workspace:

// deno.json
{ "fmt": { "singleQuote": true, "semiColons": true }, "workspace": ["sub"] }

// sub/deno.json
{ "fmt": { "singleQuote": false, "semiColons": false } }

// test.ts
console.log(   "test")

// sub/test.ts
console.log(   "sub/test")

Then run deno fmt . (the . is crucial here)

Expected result

• test.ts must have console.log('test');
• sub/test.ts must have console.log("sub/test")
• Deno must report Checked 4 files

Actual result

• test.ts has console.log("test")
  • Note: It is formatted using not deno.json, but sub/deno.json
• sub/test.ts has console.log("sub/test")
• Deno reports Checked 6 files

Research

I spent some time debugging it. It seems the additional CLI argument paths are added as include set to each workspace member FilePatterns. Thus, when Deno formats the root, it includes deno.json and test.ts; then, when Deno formats the sub workspace member, it includes sub/deno.json, sub/test.ts, and_ also . i.e. deno.json and test.ts again. Hence Checked 6 files message.

Note that deno fmt (without paths) works as expected.

[0x009922]

I would like to work on this.

I have already spent some time working on some fmt and --watch enhancements locally (which led to discovering this bug). Hopefully I can open a PR that addresses this issue targetly, or maybe it will be a larger one.