add empty string case

Author: zth

analysis/src/CompletionBackEndRevamped.ml

@@ -19,7 +19,6 @@ let findRecordField ~env ~package ~fieldName typ =
     fields |> List.find_opt (fun (field : field) -> field.fname.txt = fieldName)
 
 let completeEmptyPattern ~env ~package typ =
-  prerr_endline (Shared.typeToString typ);
   match TypeUtils.extractType ~env ~package typ with
   | None -> []
   | Some (completionType, typeArgContext) -> (
@@ -42,6 +41,11 @@ let completeEmptyPattern ~env ~package typ =
         Completion.create ?typeArgContext "false" ~includesSnippets:true
           ~insertText:"false" ~sortText:"A" ~kind:(Value typ) ~env;
       ]
+    | Tstring _ ->
+      [
+        Completion.create ?typeArgContext "\"\"" ~includesSnippets:true
+          ~insertText:"\"$0\"" ~sortText:"A" ~kind:(Value typ) ~env;
+      ]
     | _ -> [])
 
 let processCompletable ~debug ~full ~scope ~env ~pos

tests/analysis_new_tests/README.md

@@ -2,6 +2,15 @@
 
 These tests test the analysis functionality for the editor tooling.
 
+## TLDR; Contributing
+
+To make a new completion feature easy to review, follow these steps:
+
+1. Add a new (or extend an existing) test file in `test_files` with a non-working test. Make sure you use good, clear naming. Commit the (non functional) test snapshot
+2. Implement your changes
+3. Update snapshots to show things now work. Ensure no other test results have changed unexpectedly
+4. PR!
+
 ## Test Structure
 
 Test files are located in the `test_files` directory and follow a specific format:

tests/analysis_new_tests/tests/test_files/SwitchCaseCompletions.res

@@ -17,3 +17,10 @@ let x = switch true {
   | 
 //  ^com
 }
+
+// == TEST: Empty case, string
+let str = "hello"
+let x = switch str {
+  | 
+//  ^com
+}

tests/analysis_new_tests/tests/test_files/__snapshots__/SwitchCaseCompletions.res_Empty_case_string.snap

@@ -0,0 +1,21 @@
+Found Completable: Cpattern
+
+1 + // Empty case, string
+2 + let str = "hello"
+3 + let x = switch str {
+                   ---  
+4 +   | 
+5 + //  ^com
+6 + }
+
+[{
+    "label": "\"\"",
+    "kind": 12,
+    "tags": [],
+    "detail": "string",
+    "documentation": null,
+    "sortText": "A",
+    "insertText": "\"$0\"",
+    "insertTextFormat": 2
+  }]
+