Bug 1783813 - [devtools] Unify debugger initialization and thread selection. r=bomsy

We are updating more things when selecting a thread than when opening the debugger.
Let's use a unique codepath when it comes to handle a new top level target.

Differential Revision: https://phabricator.services.mozilla.com/D151552

devtools/client/debugger/src/actions/navigation.js

@@ -5,10 +5,8 @@
 import { clearDocuments } from "../utils/editor";
 import sourceQueue from "../utils/source-queue";
 
-import { evaluateExpressions } from "./expressions";
-
 import { clearWasmStates } from "../utils/wasm";
-import { getMainThread, getThreadContext } from "../selectors";
+import { getMainThread } from "../selectors";
 
 /**
  * Redux actions for the navigation state
@@ -35,18 +33,6 @@ export function willNavigate(event) {
   };
 }
 
-export function connect(url, actor) {
-  return async function({ dispatch, getState }) {
-    dispatch({
-      type: "CONNECT",
-      mainThreadActorID: actor,
-    });
-
-    const cx = getThreadContext(getState());
-    dispatch(evaluateExpressions(cx));
-  };
-}
-
 /**
  * @memberof actions/navigation
  * @static

devtools/client/debugger/src/client/firefox.js

@@ -8,6 +8,7 @@ import { features } from "../utils/prefs";
 
 import { recordEvent } from "../utils/telemetry";
 import sourceQueue from "../utils/source-queue";
+import { getContext } from "../selectors";
 
 let actions;
 let commands;
@@ -60,11 +61,11 @@ export async function onConnect(_commands, _resourceCommand, _actions, store) {
   };
   await commands.threadConfigurationCommand.updateConfiguration(options);
 
-  // We should probably only pass descriptor informations from here
-  // so only pass if that's a WebExtension toolbox.
-  // And let actions.willNavigate/NAVIGATE pass the current/selected thread
-  // from onTargetAvailable
-  await actions.connect(targetFront.url, targetFront.threadFront.actor);
+  // Select the top level target by default
+  await actions.selectThread(
+    getContext(store.getState()),
+    targetFront.threadFront.actor
+  );
 
   await targetCommand.watchTargets({
     types: targetCommand.ALL_TYPES,

devtools/client/debugger/src/reducers/pause.js

@@ -236,11 +236,6 @@ function update(state = initialPauseState(), action) {
     case "SELECT_FRAME":
       return updateThreadState({ selectedFrameId: action.frame.id });
 
-    case "CONNECT":
-      return {
-        ...initialPauseState(action.mainThreadActorID),
-      };
-
     case "PAUSE_ON_EXCEPTIONS": {
       const { shouldPauseOnExceptions, shouldPauseOnCaughtExceptions } = action;