Add an assist for OverloadedRecordDot

Author: simmsb

plugins/hls-refactor-plugin/src/Development/IDE/Plugin/CodeAction.hs

@@ -150,6 +150,7 @@ iePluginDescriptor recorder plId =
           , wrap suggestNewOrExtendImportForClassMethod
           , wrap suggestHideShadow
           , wrap suggestNewImport
+          , wrap suggestAddRecordFieldImport
           ]
           plId
    in mkExactprintPluginDescriptor recorder $ old {pluginHandlers = pluginHandlers old <> mkPluginHandler STextDocumentCodeAction codeAction }
@@ -1211,6 +1212,25 @@ suggestFixConstructorImport Diagnostic{_range=_range,..}
     in [("Fix import of " <> fixedImport, TextEdit _range fixedImport)]
   | otherwise = []
 
+suggestAddRecordFieldImport :: ExportsMap -> DynFlags -> Annotated ParsedSource -> T.Text -> Diagnostic -> [(T.Text, CodeActionKind, TextEdit)]
+suggestAddRecordFieldImport exportsMap df ps fileContents Diagnostic {..}
+  | Just fieldName <- findMissingField _message
+  , Just (range, indent) <- newImportInsertRange ps fileContents
+    = let qis = qualifiedImportStyle df
+          suggestions = nubSortBy simpleCompareImportSuggestion (constructNewImportSuggestions exportsMap (Nothing, NotInScopeThing fieldName) Nothing qis)
+      in map (\(ImportSuggestion _ kind (unNewImport -> imp)) -> (imp, kind, TextEdit range (imp <> "\n" <> T.replicate indent " "))) suggestions
+  | otherwise = []
+    where
+      findMissingField :: T.Text -> Maybe T.Text
+      findMissingField t =
+        let
+            hasfieldRegex = "((.+\\.)?HasField) \"(.+)\" ([^ ]+) ([^ ]+)"
+            regex = "(No instance for|Could not deduce):? (\\(" <> hasfieldRegex <> "\\)|‘" <> hasfieldRegex <> "’|" <> hasfieldRegex <> ")"
+            match = filter (/="") <$> matchRegexUnifySpaces t regex
+        in case match of
+               Just [_, _, _, _, fieldName, _, _] -> Just fieldName
+               _ -> Nothing
+
 -- | Suggests a constraint for a declaration for which a constraint is missing.
 suggestConstraint :: DynFlags -> ParsedSource -> Diagnostic -> [(T.Text, Rewrite)]
 suggestConstraint df (makeDeltaAst -> parsedModule) diag@Diagnostic {..}