Add inserter library as “secondary sidebar”

I am honestly starting to believe that i am already dead and
everything i do is my punishment in hell.

All i wanted is to have the list of blocks that i can insert on the
editor’s right side, like WordPress does.  At first i believed it was
a simple task, judging from the snipped at Gutenberg’s Storybook[0]:

  () => {
    const wrapperStyle = {
      margin: '24px',
      height: 400,
      border: '1px solid #f3f3f3',
      display: 'inline-block'
    };
    return <ExperimentalBlockEditorProvider>
              <div style={wrapperStyle}>
                  <BlockLibrary showInserterHelpPanel />
              </div>
          </ExperimentalBlockEditorProvider>;
  }

See? Easy! Except that they are using a
ExperimentalBlockEditorProvider, without telling us why—is it
necessary for BlockLibrary to work?—, that seems to be a private
component; and BlockLibrary, that is a component that apparently does
not exist. Where is it? How knows! There is no import in the
Storybook’s snippets; why would there be any?

As it turns out[1], that BlockLibrary is a component of
@wordpress/block-editor’s inserter component, and it is
private. Great!  What i am supposed to do, now? Lie and tell them i am
part of WordPress so that i can call unlock?  “Fortunately”, as it
were, this component is also exported in the old-fashioned way, with
the __experimental prefix.

Let’s move on.

The issue was that when the BlockLibrary is visible, Gutenberg’s
performance slows to a crawl: i can type at about one key per second,
if that many. Completely unusable, even with the styles hard coded
inside BlockEditor, meaning the error was elsewhere, but i did not
know where.

To try to figure this out, i started a new project following to the
letter their “Getting Started” document[2]; no styles, no interface,
nothing.  That done, i then added the BlockLibrary next to
BlockCanvas, to check if the problem was just having that component
all the time visible, something that WordPress doesn’t do—it closes
the library when trying to edit the document—, with encouraging
results: no sluggishness.  Wonderful!  It is something i did wrong,
which means it is something i can fix.

I kept adding more and more components, trying each time whether the
performance issue was back, until i had all the files in the new, test,
project exactly, byte by byte, like the files of this project,
including HTML and style files. However, npm run dev inside that
project, everything was fine; npm run dev here, i would have died
before writing this commit message at that speed.

I could not explain the difference other than blaming the dependencies.
I checked package.json, and sure enough there have been a new release
of Gutenberg like four hours ago, only five days after the release
of 18.5.

Of course.

“No problem,” i said to myself. “Copy package.json over here, remove
package-lock.json and node_modules, and npm install again.”  And so i
did.  And now the application was behaving different: it would not
start.

I got a bunch of error messages like this:

  Uncaught TypeError: (intermediate value)(...) is undefined
      BlockTools index.js:76
      React 12
      workLoop scheduler.development.js:266
      flushWork scheduler.development.js:239
      performWorkUntilDeadline scheduler.development.js:533
      js scheduler.development.js:571
      js scheduler.development.js:633
      __require2 chunk-MWY3P57A.js:21
      js index.js:6
      __require2 chunk-MWY3P57A.js:21
      React 2
      __require2 chunk-MWY3P57A.js:21
      js React
      __require2 chunk-MWY3P57A.js:21
      <anonymous> react-platform.js:11

I then copied package-lock.json over the new project, npm ci, and the
application would start, but it was slow too.  So, it **was**
dependency-related, but now i had another problem: even with the same
package.json and package-lock.json files, running npm update would
render the application unable to start with the same error messages as
above.

Notice that i had not specified my versions with a caret; i was
telling npm that i wanted these versions, and no other but the
versions i had been using up until now.  My guess is that some
transitive dependency has been updated, it is specified with the caret
or some other way, and has a regression or change that does not follow
semantic versioning.

The situation was, then, that i had a performance issue with Gutenberg
whose source was one of the 394 packages installed in node_modules,
therefore i could not fix it in my application, but i could not update
dependencies either, because then i had some incompatibility between
versions, and the application would not start.

I had no other option than to update Gutenberg too, and that fixed
both the incompatibility and performance issues, but has left a very
bitter taste in my mouth, and i am wondering if using Gutenberg, or
any React-based library, is the way forward: too complex, with too
many couplings, and very, very brittle.

[0]: https://wordpress.github.io/gutenberg/?path=/story/blockeditor-inserter--library-without-patterns
[1]: de56874b51/packages/block-editor/src/components/inserter/stories/index.story.js
[2]: f802107cb2/platform-docs/docs/intro.md

editor/BlockEditor.jsx

@@ -1,5 +1,5 @@
 import { InterfaceSkeleton, FullscreenMode, ComplementaryArea } from '@wordpress/interface';
-import { BlockBreadcrumb, BlockCanvas, store as blockEditorStore } from '@wordpress/block-editor';
+import { BlockBreadcrumb, BlockCanvas, __experimentalLibrary as BlockLibrary } from '@wordpress/block-editor';
 
 import Header from './Header';
 import Sidebar from './Sidebar';
@@ -28,6 +28,7 @@ export default function BlockEditor() {
 								header={ <Header /> }
 								content={ <BlockCanvas height="100%" styles={styles} /> }
 								sidebar={ <ComplementaryArea.Slot scope={ scope } /> }
+								secondarySidebar={ <BlockLibrary /> }
 								footer={ <BlockBreadcrumb /> }
 						/>
 				</>

editor/Editor.jsx

@@ -6,54 +6,15 @@ import BlockEditor from './BlockEditor';
 import './editor.scss';
 
 export default function Editor() {
-		const [ blocks, updateBlocks ] = useState();
+		const [ blocks, updateBlocks ] = useState([]);
 
-		return <BlockEditorProvider
+		return (
+				<BlockEditorProvider
 						value={ blocks }
 						onInput={ updateBlocks }
 						onChange={ updateBlocks }
-							 settings={ {
-									 __experimentalFeatures: {
-											 typography: {
-													 defaultFontSizes: true,
-													 dropCap: true,
-													 fontSizes: {
-															 default: [
-																	 {
-																			 name: "Small",
-																			 slug: "small",
-																			 size: "13px",
-																	 },
-																	 {
-																			 name: "Medium",
-																			 slug: "medium",
-																			 size: "20px",
-																	 },
-																	 {
-																			 name: "Large",
-																			 slug: "large",
-																			 size: "36px",
-																	 },
-																	 {
-																			 name: "Extra Large",
-																			 slug: "x-large",
-																			 size: "42px",
-																	 },
-															 ],
-													 },
-													 customFontSize: true,
-													 fontStyle: true,
-													 fontWeight: true,
-													 letterSpacing: true,
-													 textAlign: true,
-													 textColumns: false,
-													 textDecoration: true,
-													 textTransform: true,
-													 writingMode: false,
-											 },
-									 },
-							 } }
 				>
 						<BlockEditor/>
-					 </BlockEditorProvider>;
+				</BlockEditorProvider>
+		);
 }

package.json

@@ -11,14 +11,14 @@
 				"preview": "vite preview"
 		},
 		"dependencies": {
-				"@wordpress/block-editor": "13.0.0",
+				"@wordpress/block-editor": "^13.0.0",
-				"@wordpress/block-library": "9.0.0",
+				"@wordpress/block-library": "^9.0.0",
-				"@wordpress/components": "28.0.0",
+				"@wordpress/components": "^28.0.0",
 				"@wordpress/data": "^10.0.0",
-				"@wordpress/element": "6.0.0",
+				"@wordpress/element": "^6.0.0",
-				"@wordpress/format-library": "5.0.0",
+				"@wordpress/format-library": "^5.0.0",
-				"@wordpress/icons": "10.0.0",
+				"@wordpress/icons": "^10.0.0",
-				"@wordpress/interface": "6.0.0"
+				"@wordpress/interface": "^6.0.0"
 		},
 		"devDependencies": {
 				"@vitejs/plugin-react": "^4.3.1",