[IMP] devtools: present observed keys in a more compact way

Previously, the keys were displayed separately from the target, on top
of being displayed in bold inside the object when unfolded. This is
redundant, and in most cases you have to unfold the object anyway
because there are more keys observed than can be displayed.

The only "key" that cannot be displayed in bold inside the object is the
"key changes" magic key. This commit replaces it by a small +/- badge on
the right of the object's short content.

This commit also stops displaying observed object that are nested inside
other observed objects at the top level, as it can be confusing, and it
also heuristically gives a name to observed objects: if the observed
object is a property of the component or one of its props it will be
named accordingly, if not it will be named `[unknown]` (which may happen
when reobserving reactive objects inside a service or inside the env,
but is pretty rare in practice).

tools/devtools/src/page_scripts/owl_devtools_global_hook.js

@@ -785,57 +785,47 @@
           }
           break;
       }
-      if (child.contentType) {
-        if (child.toggled) {
-          child.children = this.loadObjectChildren(
-            child.path,
-            child.depth,
-            child.contentType,
-            child.objectType,
-            oldTree
-          );
-        }
-        return child;
-      }
-      if (obj === null) {
-        child.content = "null";
-        child.contentType = "object";
-        child.hasChildren = false;
-      } else if (obj === undefined) {
-        child.content = "undefined";
-        child.contentType = "undefined";
-        child.hasChildren = false;
-      } else {
-        obj = this.toRaw(obj);
-        switch (true) {
-          case obj instanceof Map:
-            child.contentType = "map";
-            child.hasChildren = true;
-            break;
-          case obj instanceof Set:
-            child.contentType = "set";
-            child.hasChildren = true;
-            break;
-          case obj instanceof Array:
-            child.contentType = "array";
-            child.hasChildren = obj.length > 0;
-            break;
-          case typeof obj === "function":
-            child.contentType = "function";
-            child.hasChildren = true;
-            break;
-          case obj instanceof Object:
-            child.contentType = "object";
-            child.hasChildren = Object.keys(obj).length > 0;
-            break;
-          default:
-            child.contentType = typeof obj;
-            child.hasChildren = false;
-        }
-        if (key.type === "set entry") {
-          child.content = this.serializer.serializeItem(obj, true);
+      if (!child.contentType) {
+        if (obj === null) {
+          child.content = "null";
+          child.contentType = "object";
+          child.hasChildren = false;
+        } else if (obj === undefined) {
+          child.content = "undefined";
+          child.contentType = "undefined";
+          child.hasChildren = false;
         } else {
-          child.content = this.serializer.serializeContent(obj, child.contentType);
+          obj = this.toRaw(obj);
+          switch (true) {
+            case obj instanceof Map:
+              child.contentType = "map";
+              child.hasChildren = true;
+              break;
+            case obj instanceof Set:
+              child.contentType = "set";
+              child.hasChildren = true;
+              break;
+            case obj instanceof Array:
+              child.contentType = "array";
+              child.hasChildren = obj.length > 0;
+              break;
+            case typeof obj === "function":
+              child.contentType = "function";
+              child.hasChildren = true;
+              break;
+            case obj instanceof Object:
+              child.contentType = "object";
+              child.hasChildren = Object.keys(obj).length > 0;
+              break;
+            default:
+              child.contentType = typeof obj;
+              child.hasChildren = false;
+          }
+          if (key.type === "set entry") {
+            child.content = this.serializer.serializeItem(obj, true);
+          } else {
+            child.content = this.serializer.serializeContent(obj, child.contentType);
+          }
         }
       }
       if (child.toggled) {
@@ -847,6 +837,7 @@
           oldTree
         );
       }
+      this.addHighlightedKeys(child);
       return child;
     }
 
@@ -1269,16 +1260,15 @@
           children: [],
         };
       } else {
-        const rawSubscriptions = node.subscriptions;
+        const rawSubscriptions = this.topLevelSubscriptions(node);
         component.subscriptions = {
           toggled: oldTree ? oldTree.subscriptions.toggled : true,
           children: [],
         };
         rawSubscriptions.forEach((rawSubscription, index) => {
           let subscription = {
-            keys: [],
             target: {
-              name: "target",
+              name: this.targetName(rawSubscription.target, node),
               contentType:
                 typeof rawSubscription.target === "object"
                   ? Array.isArray(rawSubscription.target)
@@ -1295,7 +1285,6 @@
               toggled: false,
               objectType: "subscription",
             },
-            keysExpanded: false,
           };
           if (
             oldTree &&
@@ -1304,13 +1293,6 @@
           ) {
             subscription.target.toggled = true;
           }
-          rawSubscription.keys.forEach((key) => {
-            if (typeof key === "symbol") {
-              subscription.keys.push(key.toString());
-            } else {
-              subscription.keys.push(key);
-            }
-          });
           if (rawSubscription.target == null) {
             if (subscription.target.contentType === "undefined") {
               subscription.target.content = "undefined";
@@ -1340,6 +1322,7 @@
               oldTree
             );
           }
+          this.addHighlightedKeys(subscription.target);
           component.subscriptions.children.push(subscription);
         });
       }
@@ -1672,6 +1655,51 @@
         inspect(obj);
       }
     }
+
+    targetName(target, node) {
+      // check on component
+      const { component } = node;
+      for (const [key, value] of Object.entries(component)) {
+        if (target === this.toRaw(value)) {
+          return key;
+        }
+      }
+      // check on props
+      for (const [key, value] of Object.entries(component.props)) {
+        if (target === this.toRaw(value)) {
+          return `props.${key}`;
+        }
+      }
+      return "[unknown]";
+    }
+
+    /**
+     * Removes subscriptions that are a direct child of another subscription:
+     * they will be reachable from the top level by expanding observed keys.
+     *
+     * @param {ComponentNode} node
+     * @returns {{ keys: PropertyKey[], target: unknown}[]} the top level
+     *  subscriptions of the node
+     */
+    topLevelSubscriptions(node) {
+      const subscriptions = node.subscriptions;
+      const toOmit = new Set(
+        subscriptions.flatMap(({ keys, target }) => keys.map((k) => this.toRaw(target[k])))
+      );
+      return subscriptions.filter(({ target }) => !toOmit.has(target));
+    }
+
+    addHighlightedKeys(child) {
+      const { path } = child;
+      const subscriptionIndex = path.findIndex((item) => typeof item !== "string");
+      if (path[subscriptionIndex]?.value === "subscriptions") {
+        const node = this.getComponentNode(path.slice(0, subscriptionIndex));
+        // Add observed keys
+        const targetToKeys = new Map(node.subscriptions.map(({ keys, target }) => [target, keys]));
+        const target = this.getObjectProperty(child.path);
+        child.keys = targetToKeys.get(target)?.map((k) => String(k));
+      }
+    }
   }
 
   function checkOwlStatus() {