Fix a bug where the initialize request would override file-based settings

Closes eng/ide/ada_language_server#1631

Author: eliericha

source/ada/lsp-ada_handlers-project_loading.adb

@@ -50,6 +50,7 @@ with URIs;
 
 with VSS.Characters;
 with VSS.Characters.Latin;
+with VSS.String_Vectors;
 with VSS.Strings;
 with VSS.Strings.Conversions;
 
@@ -118,8 +119,9 @@ package body LSP.Ada_Handlers.Project_Loading is
 
    procedure Ensure_Project_Loaded (Self : in out Message_Handler'Class) is
       use type VSS.Strings.Virtual_String;
+      use VSS.Strings.Conversions;
 
-      GPRs_Found             : Natural := 0;
+      Candidates             : VSS.String_Vectors.Virtual_String_Vector;
       Project_File           : VSS.Strings.Virtual_String :=
         Self.Configuration.Project_File;
       GPR_Configuration_File : VSS.Strings.Virtual_String :=
@@ -188,29 +190,30 @@ package body LSP.Ada_Handlers.Project_Loading is
          declare
             Files : GNATCOLL.VFS.File_Array_Access :=
               Self.Client.Root_Directory.Read_Dir (GNATCOLL.VFS.Files_Only);
-            Found : GNATCOLL.VFS.Virtual_File;
          begin
             for X of Files.all loop
                if X.Has_Suffix (".gpr") then
-                  GPRs_Found := GPRs_Found + 1;
-                  exit when GPRs_Found > 1;
-                  Found := X;
+                  Candidates.Append (LSP.Utils.To_Virtual_String (X));
                end if;
             end loop;
 
             GNATCOLL.VFS.Unchecked_Free (Files);
 
-            if GPRs_Found = 1 then
-               Project_File := LSP.Utils.To_Virtual_String (Found);
+            if Candidates.Length = 1 then
+               Project_File := Candidates.First_Element;
 
                --  Report how we found the project
                Self.Project_Status.Set_Project_Type
                  (LSP.Ada_Project_Loading.Single_Project_Found);
 
                Tracer.Trace_Text ("Found unique project: " & Project_File);
             else
-               Tracer.Trace
-                 ("Found " & GPRs_Found'Image & " projects at the root");
+               Tracer.Trace_Text
+                 ("Found "
+                  & To_Virtual_String (Candidates.Length'Image)
+                  & " projects at the root:"
+                  & VSS.Characters.Latin.Line_Feed
+                  & Candidates.Join (VSS.Characters.Latin.Line_Feed));
             end if;
          end;
       end if;
@@ -276,12 +279,12 @@ package body LSP.Ada_Handlers.Project_Loading is
          --  We didn't find a project file. Let's load an implicit project. We
          --  reach this point either because there are no GPR projects at the
          --  root, or there are more than one.
-         pragma Assert (GPRs_Found = 0 or GPRs_Found > 1);
+         pragma Assert (Candidates.Length = 0 or Candidates.Length > 1);
 
          Load_Implicit_Project
            (Self,
-            (if GPRs_Found = 0 then LSP.Ada_Project_Loading.No_Project
-             elsif GPRs_Found > 1
+            (if Candidates.Length = 0 then LSP.Ada_Project_Loading.No_Project
+             elsif Candidates.Length > 1
              then LSP.Ada_Project_Loading.Multiple_Projects
              else LSP.Ada_Project_Loading.Project_Not_Found));
       end if;

source/ada/lsp-ada_handlers.adb

@@ -94,6 +94,9 @@ with LSP.Utils;
 
 package body LSP.Ada_Handlers is
 
+   Tracer_Config : constant LSP.GNATCOLL_Tracers.Tracer :=
+     LSP.GNATCOLL_Tracers.Create ("ALS.CONFIG", GNATCOLL.Traces.On);
+
    pragma Style_Checks ("o");  --  check subprogram bodies in alphabetical ordr
 
    subtype AlsReferenceKind_Array is LSP.Structures.AlsReferenceKind_Set;
@@ -2486,6 +2489,8 @@ package body LSP.Ada_Handlers is
       if not Value.initializationOptions.Is_Empty then
          Self.Tracer.Trace
            ("Processing initializationOptions from initialize request");
+         Tracer_Config.Trace
+           ("initializationOptions = " & Value.initializationOptions'Image);
          --  The expected structure is this:
          --     "initializationOptions": {
          --        "ada": {
@@ -2495,7 +2500,12 @@ package body LSP.Ada_Handlers is
          --        }
          --     }
          declare
-            New_Configuration : LSP.Ada_Configurations.Configuration;
+            New_Configuration : LSP.Ada_Configurations.Configuration :=
+              Self.Configuration;
+            --  Start from the existing configuration so that settings parsed
+            --  from configuration files are preserved, and the settings from
+            --  initialize request are applied on top.
+
             Messages : VSS.String_Vectors.Virtual_String_Vector;
          begin
             --  Parse the configuration.
@@ -3932,6 +3942,8 @@ package body LSP.Ada_Handlers is
      (Self  : in out Message_Handler;
       Value : LSP.Ada_Configurations.Configuration'Class) is
    begin
+      Tracer_Config.Trace ("Setting configuration: " & Value'Image);
+
       Self.Configuration := LSP.Ada_Configurations.Configuration (Value);
 
       --  The base configuration is still the default one, meaning that

testsuite/ada_lsp/config_local/test.py

@@ -19,3 +19,16 @@ async def func(lsp: ALSLanguageClient) -> None:
     response = await lsp.getCurrentProject()
     assert response
     assertEqual(response, URI("non-root/p2.gpr"))
+
+
+@test(als_settings={})
+async def test_init_override(lsp: ALSLanguageClient) -> None:
+    # In this test we want to check that settings obtained in the initializationOptions
+    # of the 'initialize' request are interpreted on top of the file-based
+    # configuration.
+    #
+    # To check that we send an empty dictionary of settings in the initialize request
+    # (the 'als_settings' argument above), and we check that the applicable project is
+    # still the one specified in .als.json, i.e. the initialize request did not
+    # overwrite the file settings.
+    assertEqual(await lsp.getCurrentProject(), URI("non-root/p2.gpr"))

testsuite/ada_lsp/config_priority/test.py

@@ -1,6 +1,6 @@
 """
-The goal of this test is to check that when --config CONFIG_FILE is given, that
-configuration is loaded.
+The goal of the tests below is to check the priority with which the ALS considers
+configuration files and the initialize request.
 
 To test that we create a unique p1.gpr at the root. If there was no configuration,
 p1.gpr would be loaded automatically. It's a failure sentinel.