Concurrent runs still failing.

[Paul Williamson]

We're still struggling with concurrent Danger runs, even after the changes in #530

We get a little further this time, but somehow either Danger JS or Danger Swift is trying to write to the same location. I've run a test with two pipelines on the mac, with debug enabled.

The first fails:

2022-09-16T13:26:35.491Z danger:process_runner Preparing to run: .build/debug/danger-swift,runner,/snapshot/danger-js/distribution/commands/danger-ci.js,--process,.build/debug/danger-swift,--passURLForDSL,-i,danger_ci,-f,--cwd,../
2022-09-16T13:26:35.491Z danger:runDangerSubprocess Running sub-process: danger-swift - runner,/snapshot/danger-js/distribution/commands/danger-ci.js,--process,.build/debug/danger-swift,--passURLForDSL,-i,danger_ci,-f,--cwd,../
2022-09-16T13:26:35.500Z danger:runDangerSubprocess Started passing in STDIN via the URL: danger://dsl//var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger-dsl.json
2022-09-16T13:26:35.500Z danger:runDangerSubprocess Passed DSL in via STDIN
Ran with: /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger/8B52C17F-7357-4BF2-BC85-5FB55F2448AC/_tmp_dangerfile.swift runner /snapshot/danger-js/distribution/commands/danger-ci.js --process .build/debug/danger-swift --passURLForDSL -i danger_ci -f --cwd ../ /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger-dsl.json /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger/8B52C17F-7357-4BF2-BC85-5FB55F2448AC/danger-response.json
ERROR: could not find DSL JSON at path: /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger-dsl.json
Launching Danger Swift runner (v3.14.0)
Got URL for JSON: /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger-dsl.json
Created a temporary file for the Dangerfile DSL at: /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger-dsl.json
Running Dangerfile at: Dangerfile.swift
Preparing to compile
Running: /Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/swift --driver-mode=swift -L /private/tmp/gitlab-runner-builds/245930/Danger/.build/debug -I /private/tmp/gitlab-runner-builds/245930/Danger/.build/debug -lDangerDeps /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger/8B52C17F-7357-4BF2-BC85-5FB55F2448AC/_tmp_dangerfile.swift runner /snapshot/danger-js/distribution/commands/danger-ci.js --process .build/debug/danger-swift --passURLForDSL -i danger_ci -f --cwd ../ /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger-dsl.json /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger/8B52C17F-7357-4BF2-BC85-5FB55F2448AC/danger-response.json
Completed evaluation
ERROR: Dangerfile eval failed at Dangerfile.swift
ERROR: Could not get the results JSON file at /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger/8B52C17F-7357-4BF2-BC85-5FB55F2448AC/danger-response.json

While the second completes fine:

2022-09-16T13:26:35.135Z danger:process_runner Preparing to run: .build/debug/danger-swift,runner,/snapshot/danger-js/distribution/commands/danger-ci.js,--process,.build/debug/danger-swift,--passURLForDSL,-i,danger_ci,-f,--cwd,../
2022-09-16T13:26:35.135Z danger:runDangerSubprocess Running sub-process: danger-swift - runner,/snapshot/danger-js/distribution/commands/danger-ci.js,--process,.build/debug/danger-swift,--passURLForDSL,-i,danger_ci,-f,--cwd,../
2022-09-16T13:26:35.162Z danger:runDangerSubprocess Started passing in STDIN via the URL: danger://dsl//var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger-dsl.json
2022-09-16T13:26:35.162Z danger:runDangerSubprocess Passed DSL in via STDIN
Ran with: /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger/C31A4E15-B2D0-4622-AA41-EC29822D0386/_tmp_dangerfile.swift runner /snapshot/danger-js/distribution/commands/danger-ci.js --process .build/debug/danger-swift --passURLForDSL -i danger_ci -f --cwd ../ /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger-dsl.json /var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger/C31A4E15-B2D0-4622-AA41-EC29822D0386/danger-response.json
Decoding the DSL into Swift types
Setting up to dump results
Sending results back to Danger
Sending results back to Danger
2022-09-16T13:26:59.330Z danger:runDangerSubprocess Got JSON URL from STDOUT, results are at: 
danger-results://var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger/C31A4E15-B2D0-4622-AA41-EC29822D0386/danger-response.json
Launching Danger Swift runner (v3.14.0)

Notice theres a URL which is identical in both runs: danger://dsl//var/folders/0h/c4gthkj13sz3hb1z4fwpnd3c0000gp/T/danger-dsl.json

I'm happy to look into this, but I'm not entirely sure if this a problem with Danger JS or Swift. If you wouldn't mind taking a look and giving me a clue, I'd get cracking.

[Paul Williamson]

Actually, I think I see the issue on DangerJS:

  const sendDSLToSubprocess = () => {
    if (exec.options.passURLForDSL) {
      const resultsPath = join(tmpdir(), "danger-dsl.json")
      writeFileSync(resultsPath, dslJSONString, "utf8")
      const url = `danger://dsl/${resultsPath}`
      d(`Started passing in STDIN via the URL: ${url}`)
      child.stdin.write(url)
      child.stdin.end()
    } else {
      d(`Started passing in STDIN`)
      child.stdin.write(dslJSONString)
      child.stdin.end()
    }
    d(`Passed DSL in via STDIN`)
  }

https://github.com/danger/danger-js/blob/a6b40e953ff318c6230bf0f09152e4ba58cd567f/source/commands/utils/runDangerSubprocess.ts#L55-L69

[Paul Williamson]

After more research, it's clear this is an issue in danger-js so I've opened an issue there instead.