Add an empty Custom.hs to simplify site-specific patching

CHANGELOG.md

@@ -10,6 +10,7 @@
                 to specify search paths for sourced files.
 - json1 format like --format=json but treats tabs as single characters
 - Recognize FLAGS variables created by the shflags library.
+- Site-specific changes can now be made in Custom.hs for ease of patching
 - SC2154: Also warn about unassigned uppercase variables (optional)
 - SC2252: Warn about `[ $a != x ] || [ $a != y ]`, similar to SC2055
 - SC2251: Inform about ineffectual ! in front of commands

ShellCheck.cabal

@@ -74,6 +74,7 @@ library
       ShellCheck.AnalyzerLib
       ShellCheck.Checker
       ShellCheck.Checks.Commands
+      ShellCheck.Checks.Custom
       ShellCheck.Checks.ShellSupport
       ShellCheck.Data
       ShellCheck.Fixer

src/ShellCheck/Analyzer.hs

@@ -25,6 +25,7 @@ import ShellCheck.Interface
 import Data.List
 import Data.Monoid
 import qualified ShellCheck.Checks.Commands
+import qualified ShellCheck.Checks.Custom
 import qualified ShellCheck.Checks.ShellSupport
 
 
@@ -41,6 +42,7 @@ analyzeScript spec = newAnalysisResult {
 
 checkers params = mconcat $ map ($ params) [
     ShellCheck.Checks.Commands.checker,
+    ShellCheck.Checks.Custom.checker,
     ShellCheck.Checks.ShellSupport.checker
     ]
 

src/ShellCheck/Checks/Custom.hs

@@ -0,0 +1,21 @@
+{-
+    This empty file is provided for ease of patching in site specific checks.
+    However, there are no guarantees regarding compatibility between versions.
+-} 
+
+{-# LANGUAGE TemplateHaskell #-}
+module ShellCheck.Checks.Custom (checker, ShellCheck.Checks.Custom.runTests) where
+
+import ShellCheck.AnalyzerLib
+import Test.QuickCheck
+
+checker :: Parameters -> Checker
+checker params = Checker {
+    perScript = const $ return (),
+    perToken = const $ return ()
+  }
+
+prop_CustomTestsWork = True
+
+return []
+runTests = $quickCheckAll

test/shellcheck.hs

@@ -6,6 +6,7 @@ import qualified ShellCheck.Analytics
 import qualified ShellCheck.AnalyzerLib
 import qualified ShellCheck.Checker
 import qualified ShellCheck.Checks.Commands
+import qualified ShellCheck.Checks.Custom
 import qualified ShellCheck.Checks.ShellSupport
 import qualified ShellCheck.Fixer
 import qualified ShellCheck.Formatter.Diff
@@ -18,6 +19,7 @@ main = do
         ,ShellCheck.AnalyzerLib.runTests
         ,ShellCheck.Checker.runTests
         ,ShellCheck.Checks.Commands.runTests
+        ,ShellCheck.Checks.Custom.runTests
         ,ShellCheck.Checks.ShellSupport.runTests
         ,ShellCheck.Fixer.runTests
         ,ShellCheck.Formatter.Diff.runTests