Fix #4205 (step 6): Alias 'colour' for 'color'

Allow the British English spelling of 'color' (colour) as aliases. Implemented at the command line for `--color`, `--stack-colors` and `stack ls stack-colors`. Implemented in yaml configuration files for `color:` and `stack-colors:` (in each case, the American spelling is the alternative that has priority).

The documentation in `yaml_configuration.md` is updated, accordingly.

ChangeLog.md

@@ -26,6 +26,9 @@ Other enhancements:
   non-project-specific yaml configuration parameter, allows a stack user to
   redefine the default styles that stack uses to color some of its output. See
   `stack --help` for more information.
+* British English spelling of 'color' (colour) accepted as an alias for
+  `--color`, `--stack-colors`, `stack ls stack-colors` at the command line and
+  for `color:` and `stack-colors:` in yaml configuration files.
 * New build option `--ddump-dir`. (See [#4225](https://github.com/commercialhaskell/stack/issues/4225))
 
 Bug fixes:

doc/yaml_configuration.md

@@ -1025,6 +1025,9 @@ The color use can also be set at the command line using the equivalent
 `--color=<WHEN>` global option. Color use set at the command line takes
 precedence over that set in a yaml configuration file.
 
+(The British English spelling (colour) is also accepted. In yaml configuration
+files, the American spelling is the alternative that has priority.)
+
 ### stack-colors
 
 Stack uses styles to format some of its output. The default styles do not work
@@ -1053,4 +1056,9 @@ terminal theme might wish to set the styles as follows:
 ```yaml
 stack-colors: error=31:good=32:shell=35:dir=34:recommendation=32:target=95:module=35:package-component=95
 ```
-The styles can also be set at the command line using the equivalent `--stack-colors=<STYLES>` global option. Styles set at the command line take precedence over those set in a yaml configuration file.
+The styles can also be set at the command line using the equivalent `--stack-colors=<STYLES>`
+global option. Styles set at the command line take precedence over those set in
+a yaml configuration file.
+
+(The British English spelling (colour) is also accepted. In yaml configuration
+files, the American spelling is the alternative that has priority.)

src/Stack/Ls.hs

@@ -133,7 +133,14 @@ lsStylesCmd :: OA.Mod OA.CommandFields LsCmds
 lsStylesCmd =
     OA.command
         "stack-colors"
-        (OA.info lsStylesOptsParser (OA.progDesc "View stack's output styles"))
+        (OA.info lsStylesOptsParser
+                 (OA.progDesc "View stack's output styles"))
+    <>
+    OA.command
+        "stack-colours"
+        (OA.info lsStylesOptsParser
+                 (OA.progDesc "View stack's output styles (alias for \
+                              \'stack-colors')"))
 
 data Snapshot = Snapshot
     { snapId :: Text

src/Stack/Options/ConfigParser.hs

@@ -145,6 +145,7 @@ configOptsParser currentDir hide0 =
              hide)
     <*> optionalFirst (option readColorWhen
              ( long "color"
+            <> long "colour"
             <> metavar "WHEN"
             <> completeWith ["always", "never", "auto"]
             <> help "Specify when to use color in output; WHEN is 'always', \

src/Stack/Options/GlobalParser.hs

@@ -35,6 +35,7 @@ globalOptsParser currentDir kind defLogLevel =
         hide <*>
     option readStyles
          (long "stack-colors" <>
+          long "stack-colours" <>
           metavar "STYLES" <>
           value mempty <>
           help "Specify stack's output styles; STYLES is a colon-delimited \

src/Stack/Types/Config.hs

@@ -891,8 +891,16 @@ parseConfigMonoidObject rootDir obj = do
     configMonoidSaveHackageCreds <- First <$> obj ..:? configMonoidSaveHackageCredsName
     configMonoidHackageBaseUrl <- First <$> obj ..:? configMonoidHackageBaseUrlName
     configMonoidIgnoreRevisionMismatch <- First <$> obj ..:? configMonoidIgnoreRevisionMismatchName
-    configMonoidColorWhen <- First <$> obj ..:? configMonoidColorWhenName
-    configMonoidStyles <- fromMaybe mempty <$> obj ..:? configMonoidStylesName
+
+    configMonoidColorWhenPrimary <- obj ..:? configMonoidColorWhenName
+    configMonoidColorWhenAlternative <- obj ..:? configMonoidColorWhenAlternativeName
+    let configMonoidColorWhen =  First $   configMonoidColorWhenPrimary
+                                       <|> configMonoidColorWhenAlternative
+
+    configMonoidStylesPrimary <- obj ..:? configMonoidStylesName
+    configMonoidStylesAlternative <- obj ..:? configMonoidStylesAlternativeName
+    let configMonoidStyles = fromMaybe mempty $   configMonoidStylesPrimary
+                                              <|> configMonoidStylesAlternative
 
     return ConfigMonoid {..}
   where
@@ -1041,9 +1049,15 @@ configMonoidIgnoreRevisionMismatchName = "ignore-revision-mismatch"
 configMonoidColorWhenName :: Text
 configMonoidColorWhenName = "color"
 
+configMonoidColorWhenAlternativeName :: Text
+configMonoidColorWhenAlternativeName = "colour"
+
 configMonoidStylesName :: Text
 configMonoidStylesName = "stack-colors"
 
+configMonoidStylesAlternativeName :: Text
+configMonoidStylesAlternativeName = "stack-colours"
+
 data ConfigException
   = ParseConfigFileException (Path Abs File) ParseException
   | ParseCustomSnapshotException Text ParseException