From 1ca233484604eea2a1fc2027c6dfc8d7a90f5f89 Mon Sep 17 00:00:00 2001
From: Fenner Macrae <13209544+fennerm@users.noreply.github.com>
Date: Tue, 26 Jun 2018 16:58:34 -0700
Subject: [PATCH] Fix prospector empty string error

Prospector linter is raising error when no warnings are present in file
(#1680). Copied fix from #779.
---
 ale_linters/python/prospector.vim          | 4 ++++
 test/handler/test_prospector_handler.vader | 5 +++++
 2 files changed, 9 insertions(+)

diff --git a/ale_linters/python/prospector.vim b/ale_linters/python/prospector.vim
index 66af598a..f2968a05 100644
--- a/ale_linters/python/prospector.vim
+++ b/ale_linters/python/prospector.vim
@@ -23,6 +23,10 @@ endfunction
 function! ale_linters#python#prospector#Handle(buffer, lines) abort
     let l:output = []
 
+    if empty(a:lines)
+        return []
+    endif
+
     let l:prospector_error = json_decode(join(a:lines, ''))
 
     for l:error in l:prospector_error.messages
diff --git a/test/handler/test_prospector_handler.vader b/test/handler/test_prospector_handler.vader
index 7962f6cd..935c37da 100644
--- a/test/handler/test_prospector_handler.vader
+++ b/test/handler/test_prospector_handler.vader
@@ -156,3 +156,8 @@ Execute(Ignoring trailing whitespace messages should work):
   \ '  ]',
   \ '}',
   \ ])
+
+Execute(The prospector handler should handle empty output):
+  AssertEqual
+  \ [],
+  \ ale_linters#python#prospector#Handle(bufnr(''), [])