repo: Add exit code for explicit test.

Also fixes regression form #1774:

In #1774, I switched `ExpandEnvironmentVariables` to `$env`, which
breaks the subsequent empty string checks.
`$env:APPVEYOR_PULL_REQUEST_NUMBER`, returns `NULL`, when commit is not
yet associated with PR.

This PR adds null or empty check along with
minor improvement for `Get-Content` (instead of .NET IO).

.gitignore

@@ -50,6 +50,7 @@ libsass/*
 *.a
 *.suo
 *.sdf
+*.opendb
 *.opensdf
 a.out
 libsass.js

appveyor.yml

@@ -27,8 +27,7 @@ install:
  if ($env:Compiler -eq "mingw" -AND -Not (Test-Path "C:\mingw64")) {
  # Install MinGW.
  $file = "x86_64-4.9.2-release-win32-seh-rt_v4-rev3.7z"
- $url = "https://bintray.com/artifact/download/drewwells/generic/$file"
- Invoke-WebRequest -UserAgent wget -Uri $url -OutFile $file
+ wget https://bintray.com/artifact/download/drewwells/generic/$file -o $file
  &7z x -oC:\ $file > $null
  }
  - set PATH=C:\mingw64\bin;%PATH%
@@ -53,14 +52,12 @@ build_script:
 test_script:
  - ps: |
  $PRNR = $env:APPVEYOR_PULL_REQUEST_NUMBER
- if ($PRNR -ne "") {
+ if ($PRNR) {
  echo "Fetching info for PR $PRNR"
- $request = (New-Object System.Net.WebClient)
- $request.headers['User-Agent'] = "Mozilla/5.0"
- $request.DownloadFile( "https://api.github.com/repos/sass/libsass/pulls/$PRNR", 'pr.json')
- $json = [IO.File]::ReadAllText('pr.json')
+ wget https://api.github.com/repos/sass/libsass/pulls/$PRNR -o pr.json
+ $json = Get-Content pr.json -Raw
  $SPEC_PR = [regex]::match($json,'sass\/sass-spec(#|\/pull\/)([0-9]+)').Groups[2].Value
- if ($SPEC_PR -ne "") {
+ if ($SPEC_PR) {
  echo "Checkout sass spec PR $SPEC_PR"
  git -C sass-spec fetch -q -u origin pull/$SPEC_PR/head:ci-spec-pr-$SPEC_PR
  git -C sass-spec checkout -q --force ci-spec-pr-$SPEC_PR
@@ -75,6 +72,7 @@ test_script:
  &$env:TargetPath ./input.scss 2>&1>$null
  if(-not($?)) {
  echo "Failed!"
+ exit 1
  } else {
  echo "Success!"
  }