Allow parsing remote files as typescript

Currently, the transpiler.ts makes an assumption that the filename will
always end with .ts, but this is incorrect in the case of remote
dangerfiles that have refs attached, for example
abc/123/dangerfile.ts?feature/branch
Due to this, typescript parsing will always fail for remote files.

This commit adds a new parameter to the transpiler function, which
parses the filename differently if the file is a remote one. This change
also had to cascade up the stack to the runDangerfileEnvironment
function, where we now accept a set of tuples, where the first is the
filename, and the second is if it is remote or not. The only place the
remote flag is being set currently is in the GitHub runner, where we
download the remote dangerfile.

Finally, the pr subcommand failed to use the remote feature correctly,
since the file would never exist when the command is first run. The
check for the file has been removed, simply leaving behind the same
check that is everywhere else.

source/commands/danger-pr.ts

@@ -7,7 +7,6 @@ import prettyjson from "prettyjson"
 import { FakeCI } from "../ci_source/providers/Fake"
 import { pullRequestParser } from "../platforms/pullRequestParser"
 import { dangerfilePath } from "./utils/fileUtils"
-import validateDangerfileExists from "./utils/validateDangerfileExists"
 import setSharedArgs, { SharedCLI } from "./utils/sharedDangerfileArgs"
 import { jsonDSLGenerator } from "../runner/dslGenerator"
 import { prepareDangerDSL } from "./utils/runDangerSubprocess"
@@ -94,8 +93,7 @@ if (program.args.length === 0) {
       const isJSON = app.js || app.json
       const note = isJSON ? console.error : console.log
       note(`Starting Danger PR on ${pr.repo}#${pr.pullRequestNumber}`)
-
-      if (customProcess || isJSON || validateDangerfileExists(dangerfilePath(program))) {
+      if (customProcess || isJSON || dangerfilePath(program)) {
         if (!customProcess) {
           d(`executing dangerfile at ${dangerfilePath(program)}`)
         }

source/commands/danger-runner.ts

@@ -62,7 +62,7 @@ const run = (config: SharedCLI) => async (jsonString: string) => {
   if (platform.executeRuntimeEnvironment) {
     await platform.executeRuntimeEnvironment(inline.runDangerfileEnvironment, dangerFile, runtimeEnv)
   } else {
-    await inline.runDangerfileEnvironment([dangerFile], [undefined], runtimeEnv)
+    await inline.runDangerfileEnvironment([[dangerFile, false]], [undefined], runtimeEnv)
   }
 }
 

source/platforms/GitHub.ts

@@ -121,6 +121,7 @@ const executeRuntimeEnvironment = async (
   // dangerfile comes from the web, and do all the prefixing etc
   let path: string
   let content: string
+  let remote: boolean = false
   if (existsSync(dangerfilePath)) {
     path = dangerfilePath
     content = readFileSync(dangerfilePath, "utf8")
@@ -142,8 +143,9 @@ const executeRuntimeEnvironment = async (
     // Chop off the danger import
     const newDangerfile = cleanDangerfile(dangerfileContent)
 
+    remote = true
     // Cool, transpile it into something we can run
-    content = transpiler(newDangerfile, dangerfilePath)
+    content = transpiler(newDangerfile, dangerfilePath, remote)
   }
 
   // If there's an event.json - we should always pass it inside the default export
@@ -155,7 +157,7 @@ const executeRuntimeEnvironment = async (
   }
 
   // Actually start up[ the runtime evaluation
-  await start([path], [content], environment, defaultExport)
+  await start([[path, remote]], [content], environment, defaultExport)
 
   // Undo the runtime
   restoreOriginalModuleLoader()

source/runner/Executor.ts

@@ -99,7 +99,7 @@ export class Executor {
     // If an eval of the Dangerfile fails, we should generate a
     // message that can go back to the CI
     try {
-      results = await this.runner.runDangerfileEnvironment([file], [undefined], runtime)
+      results = await this.runner.runDangerfileEnvironment([[file, false]], [undefined], runtime)
     } catch (error) {
       results = this.resultsForError(error as Error)
     }

source/runner/runners/inline.ts

@@ -55,7 +55,7 @@ const runAllScheduledTasks = async (results: DangerRuntimeContainer) => {
  * @returns {DangerResults} the results of the run
  */
 export const runDangerfileEnvironment = async (
-  filenames: string[],
+  filenames: [string, boolean][],
   originalContents: (string | undefined)[] | undefined,
   environment: DangerContext,
   injectedObjectToExport?: any,
@@ -84,11 +84,16 @@ export const runDangerfileEnvironment = async (
   // Loop through all files and their potential contents, they edit
   // results inside the env, so no need to keep track ourselves
 
-  for (const filename of filenames) {
-    const index = filenames.indexOf(filename)
-    const originalContent = (originalContents && originalContents[index]) || fs.readFileSync(filename, "utf8")
+  for (let index = 0; index < filenames.length; index++) {
+    const [filename, remote] = filenames[index]
+    let fn: string = filename
+    if (remote) {
+      d(`File ${filename} is a remote dangerfile`)
+      fn = filename.split("@")[0]
+    }
+    const originalContent = (originalContents && originalContents[index]) || fs.readFileSync(fn, "utf8")
     let content = cleanDangerfile(originalContent)
-    let compiled = compile(content, filename)
+    let compiled = compile(content, filename, remote)
 
     try {
       // Move all the DSL attributes into the global scope

source/runner/runners/runner.ts

@@ -6,14 +6,15 @@ export interface DangerRunner {
    * Executes a Dangerfile at a specific path, with a context.
    * The values inside a Danger context are applied as globals to the Dangerfiles runtime.
    *
-   * @param {string[]} filenames a set of file paths for the dangerfile
+   * @param {[string, boolean][]} filenames a set of tuples of file paths for the dangerfile, with a boolean indicating
+   * if it is a remote path
    * @param {string[] | undefined[]} originalContents optional, the JS pre-compiled
    * @param {DangerContext} environment the results of createDangerfileRuntimeEnvironment
    * @param {any | undefined} injectedObjectToExport an optional object for passing into default exports
    * @returns {DangerResults} the results of the run
    */
   runDangerfileEnvironment: (
-    filenames: string[],
+    filenames: [string, boolean][],
     originalContents: string[] | undefined[] | undefined,
     environment: any,
     injectedObjectToExport?: any

source/runner/runners/utils/transpiler.ts

@@ -183,23 +183,33 @@ export const babelify = (content: string, filename: string, extraPlugins: string
   return result.code
 }
 
-export default (code: string, filename: string) => {
+export default (code: string, filename: string, remoteFile: boolean = false) => {
   if (!hasChecked) {
     checkForNodeModules()
   }
 
-  const filetype = path.extname(filename)
+  let filetype: string
+  if (remoteFile) {
+    d(`Parsing the file from the remote reference ${filename}`)
+    let [file, _] = filename.split("@")
+    filetype = path.extname(file)
+  } else {
+    filetype = path.extname(filename)
+  }
   const isModule = filename.includes("node_modules")
   if (isModule) {
     return code
   }
 
   let result = code
   if (hasNativeTypeScript && filetype.startsWith(".ts")) {
+    d("compiling with typescript")
     result = typescriptify(code, path.dirname(filename))
   } else if (hasBabel && hasBabelTypeScript && filetype.startsWith(".ts")) {
+    d("compiling as typescript with babel")
     result = babelify(code, filename, [`${babelPackagePrefix}plugin-transform-typescript`])
   } else if (hasBabel && filetype.startsWith(".js")) {
+    d("babelifying as javascript")
     result = babelify(code, filename, hasFlow ? [`${babelPackagePrefix}plugin-transform-flow-strip-types`] : [])
   }