Can't get custom diagnostics to work

[Integralist]

👋🏻 I would like to create a custom diagnostics using the tool tfproviderlintx but I have a few issues...

1. I'd like it to run on .go files but only those from a specific directory (e.g. a Terraform Provider is written in Go, but I don't want every Go project I have to use the tfproviderlintx diagnostics).

2. I'm trying to get it to run on a single file (as the command needs to be passed a file path, e.g. tfproviderlintx -XAT001=false -R018=false /Users/integralist/Code/fastly/terraform-provider-fastly/fastly/block_fastly_service_vcl.go) and although the file I'm running the below Lua configuration against should cause an error to be returned from tfproviderlintx, I'm not seeing it show up anywhere in Neovim? (I presumed it would show up in the quickfix window)

Here is my Lua configuration for null-ls and the custom diagnostic helper (for the pattern regex, there's a link to regex101.com to demonstrate the regex pattern should work given the expected output from the tfproviderlintx command)...

    use { "jose-elias-alvarez/null-ls.nvim",
      config = function()
        local null_ls = require("null-ls")
        local helpers = require("null-ls.helpers")

        null_ls.setup({
          sources = {
            require("null-ls").builtins.diagnostics.checkmake, -- https://github.com/mrtazz/checkmake
          }
        })

        -- https://github.com/jose-elias-alvarez/null-ls.nvim/blob/main/doc/HELPERS.md
        local tfproviderlintx = {
          method = null_ls.methods.DIAGNOSTICS,
          filetypes = { "go" },
          generator = null_ls.generator({
            command = "tfproviderlintx",
            args = { "-XAT001=false", "-R018=false", "$FILENAME" },
            to_stdin = true,
            from_stderr = true,
            format = "line",
            check_exit_code = function(code, stderr)
              local success = code <= 1

              if not success then
                print(stderr)
              end

              return success
            end,
            on_output = helpers.diagnostics.from_patterns({
              {
                pattern = [[(^[^:]+):(\d+):(\d+):\s([^:]+):\s(.+)$]], -- https://regex101.com/r/wytcMN/1
                groups = { "path", "row", "col", "message", "code", "message" },
              },
            }),
          }),
        }

        null_ls.register(tfproviderlintx)
      end
    }

I hope someone can help me understand what I'm doing wrong.

Thanks!

[jose-elias-alvarez]

1. We don't currently have an ideal way to handle this case, but you can use runtime_condition to make sure diagnostics only show up for buffers matching a given pattern.
2. Lua doesn't support regular expressions - it instead uses patterns, which are similar but not compatible. I'd start looking there, and I'd also enable debug mode to see what output you are getting and how your source is parsing it.

[Integralist]

Hi @jose-elias-alvarez thanks for clarifying, so I modified the code based on what I had learnt about Lua patterns compared to regexes and it looks like I only really needed to change \d to %d and \s to %s as characters classes are the same [] and so are negated character classes [^] and so is ^ as an anchor and + should mean one or more of, and () is a capture group from what I can tell still.

But I'm still not seeing the command getting run 🤔

You'll see that I even stick in a print(params) for runtime_condition to see what's passed in, along with forcing true for the time being, and the print doesn't get executed (e.g. :messages shows nothing).

    use { "jose-elias-alvarez/null-ls.nvim",
      config = function()
        local null_ls = require("null-ls")
        local helpers = require("null-ls.helpers")

        null_ls.setup({
          sources = {
            require("null-ls").builtins.diagnostics.checkmake, -- https://github.com/mrtazz/checkmake
          }
        })

        -- https://github.com/jose-elias-alvarez/null-ls.nvim/blob/main/doc/HELPERS.md
        local tfproviderlintx = {
          name = "tfproviderlintx",
          method = null_ls.methods.DIAGNOSTICS,
          filetypes = { "go" },
          runtime_condition = function(params)
            print(params)
            return true
          end,
          generator = null_ls.generator({
            command = "tfproviderlintx",
            args = { "-XAT001=false", "-R018=false", "$FILENAME" },
            to_stdin = true,
            from_stderr = true,
            format = "line",
            check_exit_code = function(code, stderr)
              local success = code <= 1

              if not success then
                print(stderr)
              end

              return success
            end,
            on_output = helpers.diagnostics.from_patterns({
              {
                pattern = [[(^[^:]+):(%d+):(%d+):%s([^:]+):%s(.+)$]], -- https://regex101.com/r/wytcMN/1 (converted using non-regex Lua patterns https://www.lua.org/pil/20.2.html)
                groups = { "path", "row", "col", "message", "code", "message" },
              },
            }),
          }),
        }

        null_ls.register(tfproviderlintx)
      end
    }

[Integralist]

For reference of errors now showing in :messages...

[Integralist]

OK I thought I'd try to restrict the diagnostics by searching the bufname path for terraform-provider- but that appears to not work as I then tested on another go project and found it was still being executed...

    use { "jose-elias-alvarez/null-ls.nvim",
      config = function()
        local null_ls = require("null-ls")
        local helpers = require("null-ls.helpers")

        null_ls.setup({
          sources = {
            require("null-ls").builtins.diagnostics.checkmake, -- https://github.com/mrtazz/checkmake
          }
        })

        local tfproviderlintx = {
          name = "tfproviderlintx",
          method = null_ls.methods.DIAGNOSTICS,
          filetypes = { "go" },
          runtime_condition = function(params)
            return params.bufname:find("terraform-provider-") ~= nil
          end,
          generator = null_ls.generator({
            command = "tfproviderlintx",
            args = { "-XAT001=false", "-R018=false", "$FILENAME" },
            to_stdin = true,
            from_stderr = true,
            format = "line",
            check_exit_code = function(code, stderr)
              local success = code < 1

              if not success then
                print(stderr)
              end

              return success
            end,
            on_output = helpers.diagnostics.from_patterns({
              {
                pattern = [[(^[^:]+):(%d+):(%d+):%s([^:]+):%s(.+)$]], -- https://regex101.com/r/wytcMN/1 (converted using non-regex Lua patterns https://www.lua.org/pil/20.2.html)
                groups = { "path", "row", "col", "message", "code", "message" },
              },
            }),
          }),
        }

        null_ls.register(tfproviderlintx)
      end
    }

[jose-elias-alvarez]

You need to pass runtime_condition into your generator options, as specified in the documentation.

[Integralist]

@jose-elias-alvarez thanks. I was originally using the CLI parsing example from the README which wasn't use the generator_factory type you linked to.

I've since updated my example to use generator_factory, and I can get it running for just Terraform projects now.

But it looks like on_output doesn't really do anything. For example, I expected it to parse the error output from the command that was executed (and display that in the LSP diagnostics window, e.g. Trouble, like I see when using a null-ls builtin).

I print the stderr inside of check_exit_code and I can see the lines of error from the command in :messages, which I would expect to be passed to on_output to parse and then pass to LSP diagnostics. So I'm obviously missing a piece of the puzzle still.

For on_output I'm using helpers.diagnostics.from_patterns as that was used in the CLI parsing example from the README, so maybe there's something wrong there? But if so I'm not sure what...

    use { "jose-elias-alvarez/null-ls.nvim",
      config = function()
        local null_ls = require("null-ls")
        local helpers = require("null-ls.helpers")

        local tfproviderlintx = {
          name = "tfproviderlintx",
          method = null_ls.methods.DIAGNOSTICS,
          filetypes = { "go" },
          generator = helpers.generator_factory({
            args = { "-XAT001=false", "-R018=false", "$FILENAME" },
            check_exit_code = function(code, stderr)
              local success = code < 1
              if not success then
                print(stderr)
              end
              return success
            end,
            command = "tfproviderlintx",
            format = "line",
            from_stderr = true,
            on_output = helpers.diagnostics.from_patterns({
              {
                pattern = [[(^[^:]+):(%d+):(%d+):%s([^:]+):%s(.+)$]],
                groups = { "path", "row", "col", "message", "code", "message" },
              },
            }),
            runtime_condition = function(params)
              return params.bufname:find("terraform%-provider%-") ~= nil
            end,
            to_stdin = true,
          }),
        }

        null_ls.setup({
          sources = {
            tfproviderlintx,
            require("null-ls").builtins.diagnostics.checkmake,
          }
        })
      end
    }

[Integralist]

Nevermind. My groups had an extra group that shouldn't have been there.

OK this is working now. Finally 🎉

Thanks for your patience.

[Integralist]

This is the final solution:

    use { "jose-elias-alvarez/null-ls.nvim",
      config = function()
        local null_ls = require("null-ls")
        local helpers = require("null-ls.helpers")

        local tfproviderlintx = {
          name = "tfproviderlintx",
          method = null_ls.methods.DIAGNOSTICS,
          filetypes = { "go" },
          generator = helpers.generator_factory({
            args = { "-XAT001=false", "-R018=false", "$FILENAME" },
            check_exit_code = function(code, stderr)
              local success = code < 1
              if not success then
                print(stderr)
              end
              return success
            end,
            command = "tfproviderlintx",
            format = "line",
            from_stderr = true,
            on_output = helpers.diagnostics.from_patterns({
              {
                pattern = [[([^:]+):(%d+):(%d+):%s([^:]+):%s(.+)]],
                groups = { "path", "row", "col", "code", "message" },
              },
            }),
            runtime_condition = function(params)
              return params.bufname:find("terraform%-provider%-") ~= nil
            end,
            to_stdin = true,
          }),
        }

        null_ls.setup({
          sources = {
            tfproviderlintx,
            require("null-ls").builtins.diagnostics.checkmake,
          }
        })
      end
    }

[jose-elias-alvarez]

Glad you figured it out!

[lo-b]

Thanks for the example, helped me out too when setting up a custom diagnostics!