feat(core): Support adding top-level metadata

packages/core/lib/metadata-delegate.js

@@ -1,7 +1,7 @@
 const assign = require('./es-utils/assign')
 
 const add = (state, section, keyOrObj, maybeVal) => {
-  if (!section) return
+  if (!section && section !== null) return
   let updates
 
   // addMetadata("section", null) -> clears section
@@ -14,11 +14,14 @@ const add = (state, section, keyOrObj, maybeVal) => {
   // exit if we don't have an updates object at this point
   if (!updates) return
 
-  // ensure a section with this name exists
-  if (!state[section]) state[section] = {}
-
-  // merge the updates with the existing section
-  state[section] = assign({}, state[section], updates)
+  if (section !== null) {
+    // ensure a section with this name exists
+    if (!state[section] || typeof state[section] !== 'object') state[section] = {}
+    // merge the updates with the existing section
+    state[section] = assign({}, state[section], updates)
+  } else {
+    assign(state, updates)
+  }
 }
 
 const get = (state, section, key) => {

packages/core/test/client.test.ts

@@ -639,6 +639,18 @@ describe('@bugsnag/core/client', () => {
       expect(client.getMetadata('a', 'b')).toBe(undefined)
       client.clearMetadata('a')
       expect(client.getMetadata('a')).toBe(undefined)
+
+      // check that top-level metadata can be added with section=null
+      client.addMetadata(null, 'top', 'val')
+      expect(client._metadata).toEqual({ top: 'val' })
+      client.addMetadata('top', 'key', 'val')
+      expect(client._metadata).toEqual({ top: { key: 'val' } })
+
+      client._metadata = {}
+
+      client.addMetadata('replace', 'key', 'origval')
+      client.addMetadata(null, 'replace', { diffkey: 'replaceval' })
+      expect(client._metadata).toEqual({ replace: { diffkey: 'replaceval' } })
     })
 
     it('can be set in config', () => {