Add random chars to files to support concurrency

Fixes #1311

CHANGELOG.md

@@ -15,7 +15,7 @@
 ## Main
 
 <!-- Your comment below this -->
-
+- Append random string to danger-results.json and danger-dsl.json files to better support concurrent processes #1311
 
 <!-- Your comment above this -->
 

source/commands/danger-runner.ts

@@ -18,6 +18,7 @@ import { getPlatformForEnv } from "../platforms/platform"
 import { tmpdir } from "os"
 import { writeFileSync } from "fs"
 import { join } from "path"
+import { randomBytes } from "crypto"
 
 const d = debug("runner")
 
@@ -72,12 +73,11 @@ nodeCleanup((exitCode: number, signal: string) => {
   const results: DangerResults = runtimeEnv.results
   d(`Process has finished with ${exitCode}, sending the results back to the host process ${signal || ""}`)
   d(
-    `Got md ${results.markdowns.length} w ${results.warnings.length} f ${results.fails.length} m ${
-      results.messages.length
-    }`
+    `Got md ${results.markdowns.length} w ${results.warnings.length} f ${results.fails.length} m ${results.messages.length}`
   )
   if (foundDSL) {
-    const resultsPath = join(tmpdir(), "danger-results.json")
+    const filename = `danger-results-${randomBytes(4).toString("hex")}.json`
+    const resultsPath = join(tmpdir(), filename)
     d(`Writing results into ${resultsPath}`)
     writeFileSync(resultsPath, JSON.stringify(results, null, 2), "utf8")
     process.stdout.write("danger-results:/" + resultsPath)

source/commands/utils/runDangerSubprocess.ts

@@ -9,6 +9,7 @@ import { markdownCode, resultsWithFailure, mergeResults } from "./reporting"
 import { readFileSync, existsSync, writeFileSync } from "fs"
 import { RunnerConfig } from "../ci/runner"
 import { tmpdir } from "os"
+import { randomBytes } from "crypto"
 
 const d = debug("runDangerSubprocess")
 
@@ -54,7 +55,8 @@ export const runDangerSubprocess = (
 
   const sendDSLToSubprocess = () => {
     if (exec.options.passURLForDSL) {
-      const resultsPath = join(tmpdir(), "danger-dsl.json")
+      const filename = `danger-dsl-${randomBytes(4).toString("hex")}.json`
+      const resultsPath = join(tmpdir(), filename)
       writeFileSync(resultsPath, dslJSONString, "utf8")
       const url = `danger://dsl/${resultsPath}`
       d(`Started passing in STDIN via the URL: ${url}`)
@@ -72,7 +74,7 @@ export const runDangerSubprocess = (
   sendDSLToSubprocess()
 
   let allLogs = ""
-  child.stdout.on("data", async data => {
+  child.stdout.on("data", async (data) => {
     const stdout: string = data.toString()
     allLogs += stdout
 
@@ -112,13 +114,13 @@ export const runDangerSubprocess = (
     }
   })
 
-  child.stderr.on("data", data => {
+  child.stderr.on("data", (data) => {
     if (data.toString().trim().length !== 0) {
       console.log(data.toString())
     }
   })
 
-  child.on("close", async code => {
+  child.on("close", async (code) => {
     d(`child process exited with code ${code}`)
     // Submit an error back to the PR
     if (code) {
@@ -149,7 +151,7 @@ const getJSONURLFromSTDOUT = (stdout: string): string | undefined => {
 /** Pulls the JSON directly out, this has proven to be less reliable  */
 const getJSONFromSTDOUT = (stdout: string): string | undefined => {
   const lines = stdout.split("\n")
-  return lines.find(line => {
+  return lines.find((line) => {
     const trimmed = line.trim()
     return (
       trimmed.startsWith("{") &&