Formatting crosstalk

[MrDOS]

Describe the bug

When one function has poorly formatted annotations, swag fmt may incorrectly modify the formatting of other functions.

To Reproduce

main.go:

package main

// @Produce json
// @Success 200 {object} string
// @Failure 400 {object} string
func A() {}

// @Description Description of B.
// @Produce json
// @Success 200 {array} string
// @Failure 400 {object} string
func B() {}

Then run swag fmt.

The resulting main.go:

package main

// @Produce     json
// @Success 200 {object} string
// @Failure     400 {object} string
func A() {}

// @Description Description of B.
// @Produce json
// @Success     200 {array}  string
// @Failure 400 {object} string
func B() {}

Expected behavior

• I do not expect the comments on function A to change.
• I expect the Swag attributes on function B to have been correctly aligned.

package main

// @Produce json
// @Success 200 {object} string
// @Failure 400 {object} string
func A() {}

// @Description Description of B.
// @Produce     json
// @Success     200 {array}  string
// @Failure     400 {object} string
func B() {}

Your swag version

$ swag --version
swag version v1.8.5

...but I can reproduce on v1.8.4 and the latest development version.

Your go version

$ go version
go version go1.18.5 darwin/arm64

...but I can reproduce on Go 1.19, and on Linux AMD64.

Desktop (please complete the following information):

• OS: macOS 12.5.1
• Browser: n/a
• Version: n/a

Additional context

This is the most messed-up example of this that I could come up with. It seems to be extremely sensitive to how well-formatted the input is to begin with, and the success/failure types.

• Half-indenting attributes or changing their types produces further wild variations in output. For example, change B's success type from {array} string to {object} string, and all three of A's attributes will be indented equally, but none of B's:

  package main
  
  // @Produce     json
  // @Success     200 {object} string
  // @Failure     400 {object} string
  func A() {}
  
  // @Description Description of B.
  // @Produce json
  // @Success 200 {object} string
  // @Failure 400 {object} string
  func B() {}

  Or, change A's success and failure types from {object} string to just string, and A's produce attribute and B's success and failure attributes will be indented:

  package main
  
  // @Produce     json
  // @Success 200 string
  // @Failure 400 string
  func A() {}
  
  // @Description Description of B.
  // @Produce json
  // @Success     200 {array}  string
  // @Failure     400 {object} string
  func B() {}

• If there is another function between A and B, it will not be affected (but A and B both still will be).

• This does not happen if the comments on C are already correctly formatted.

• I have only been able to trigger this behaviour with a @Description attribute on the second function, which I suspect has something to do with that attribute being longer than any on the first.

[ubogdan]

@MrDOS This is an Open Souce project, and you can contribute via PR to improve it.

[MrDOS]

@ubogdan, sure thing: see #1317.