Re-run history tests, which can fail randomly

test/test_history_saving.vader

@@ -41,6 +41,7 @@ Before:
 After:
   Restore
 
+  unlet! g:expected_results
   unlet! b:ale_fixers
   unlet! b:ale_enabled
   " Clear the history we changed.
@@ -67,6 +68,11 @@ Given foobar (Some imaginary filetype):
 Execute(History should be set when commands are run):
   AssertEqual 'foobar', &filetype
 
+  let g:expected_results = ['command', 'exit_code', 'job_id', 'status']
+
+  " Retry this test until it works. This one can randomly fail.
+  for g:i in range(has('nvim-0.3') || has('win32') ? 5 : 1)
+    let b:ale_history = []
     call ale#Lint()
     call ale#engine#WaitForJobs(2000)
 
@@ -76,7 +82,13 @@ Execute(History should be set when commands are run):
     \)
 
     AssertEqual 1, len(g:history)
-  AssertEqual sort(['status', 'exit_code', 'job_id', 'command']), sort(keys(g:history[0]))
+
+    if sort(keys(g:history[0])) == g:expected_results
+      break
+    endif
+  endfor
+
+  AssertEqual g:expected_results, sort(keys(g:history[0]))
 
   if has('win32')
     AssertEqual 'cmd /s/c "echo command history test"', g:history[0].command
@@ -103,14 +115,24 @@ Execute(History should include command output if logging is enabled):
   AssertEqual 'foobar', &filetype
 
   let g:ale_history_log_output = 1
+  let g:expected_results = ['command history test']
 
+  " Retry this test until it works. This one can randomly fail.
+  for g:i in range(has('nvim-0.3') || has('win32') ? 5 : 1)
+    let b:ale_history = []
     call ale#Lint()
     call ale#engine#WaitForJobs(2000)
 
     let g:history = ale#history#Get(bufnr(''))
 
     AssertEqual 1, len(g:history)
-  AssertEqual ['command history test'], g:history[0].output
+
+    if get(g:history[0], 'output', []) == g:expected_results
+      break
+    endif
+  endfor
+
+  AssertEqual g:expected_results, get(g:history[0], 'output', [])
 
 Execute(History items should be popped after going over the max):
   let b:ale_history = map(range(20), '{''status'': ''started'', ''job_id'': v:val, ''command'': ''foobar''}')