Add missing awaits (#379)

* auth-helper: properly await replacement of the token value in the config

After writing the `.extraheader` config, we manually replace the token
with the actual value. This is done in an `async` function, but we were
not `await`ing the result.

In our tests, this commit fixes a flakiness we observed where
`remote.origin.url` sometimes (very rarely, actually) is not set for
submodules. Our interpretation is that the configs are in the process of
being rewritten with the correct token value _while_ another `git
config` that wants to set the `insteadOf` value is reading the config,
which is currently empty.

A more idiomatic way to fix this in Typescript would use
`Promise.all()`, like this:

      await Promise.all(
        configPaths.map(async configPath => {
          core.debug(`Replacing token placeholder in '${configPath}'`)
          await this.replaceTokenPlaceholder(configPath)
        })
      )

However, during review of https://github.com/actions/checkout/pull/379
it was decided to keep the `for` loop in the interest of simplicity.

Reported by Ian Lynagh.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

* downloadRepository(): await the result of recursive deletions

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

* Ask ESLint to report floating Promises

This rule is quite helpful in avoiding hard-to-debug missing `await`s.

Note: there are two locations in `src/main.ts` that trigger warnings:
the `run()` and the `cleanup()` function are called without `await` and
without any `.catch()` clause.

In the initial version of https://github.com/actions/checkout/pull/379,
this was addressed by adding `.catch()` clauses. However, it was
determined that this is boilerplate code that will need to be fixed in a
broader way.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

* Rebuild

This trick was brought to you by `npm ci && npm run build`. Needed to
get the PR build to pass.

Signed-off-by: Johannes Schindelin <johannes.schindelin@gmx.de>

src/git-auth-helper.ts

@@ -148,7 +148,7 @@ class GitAuthHelper {
         output.match(/(?<=(^|\n)file:)[^\t]+(?=\tremote\.origin\.url)/g) || []
       for (const configPath of configPaths) {
         core.debug(`Replacing token placeholder in '${configPath}'`)
-        this.replaceTokenPlaceholder(configPath)
+        await this.replaceTokenPlaceholder(configPath)
       }
 
       if (this.settings.sshKey) {

src/github-api-helper.ts

@@ -47,7 +47,7 @@ export async function downloadRepository(
   } else {
     await toolCache.extractTar(archivePath, extractPath)
   }
-  io.rmRF(archivePath)
+  await io.rmRF(archivePath)
 
   // Determine the path of the repository content. The archive contains
   // a top-level folder and the repository content is inside.
@@ -70,7 +70,7 @@ export async function downloadRepository(
       await io.mv(sourcePath, targetPath)
     }
   }
-  io.rmRF(extractPath)
+  await io.rmRF(extractPath)
 }
 
 /**