Enable strictNullChecks

blots/block.ts

@@ -53,7 +53,7 @@ class Block extends BlockBlot {
     }
     if (value.length === 0) return;
     const lines = value.split('\n');
-    const text = lines.shift();
+    const text = lines.shift() as string;
     if (text.length > 0) {
       if (index < this.length() - 1 || this.children.tail == null) {
         super.insertAt(Math.min(index, this.length() - 1), text);
@@ -66,6 +66,7 @@ class Block extends BlockBlot {
     // eslint-disable-next-line @typescript-eslint/no-this-alias
     let block: Blot | this = this;
     lines.reduce((lineIndex, line) => {
+      // @ts-expect-error Fix me later
       block = block.split(lineIndex, true);
       block.insertAt(0, line);
       return line.length;
@@ -114,6 +115,7 @@ class Block extends BlockBlot {
         this.parent.insertBefore(clone, this);
         return this;
       }
+      // @ts-expect-error Fix me later
       this.parent.insertBefore(clone, this.next);
       return clone;
     }
@@ -169,9 +171,11 @@ class BlockEmbed extends EmbedBlot {
     });
     const ref = this.split(index);
     blocks.forEach(block => {
+      // @ts-expect-error Fix me later
       this.parent.insertBefore(block, ref);
     });
     if (text) {
+      // @ts-expect-error Fix me later
       this.parent.insertBefore(this.scroll.create('text', text), ref);
     }
   }

blots/cursor.ts

@@ -67,6 +67,7 @@ class Cursor extends EmbedBlot {
 
   remove() {
     super.remove();
+    // @ts-expect-error Fix me later
     this.parent = null;
   }
 
@@ -79,6 +80,7 @@ class Cursor extends EmbedBlot {
       this.domNode.lastChild != null &&
       this.domNode.lastChild !== this.textNode
     ) {
+      // @ts-expect-error Fix me later
       this.domNode.parentNode.insertBefore(
         this.domNode.lastChild,
         this.domNode,
@@ -171,6 +173,7 @@ class Cursor extends EmbedBlot {
   // And then "x" will be inserted after `<a/>`:
   //    <span class="ql-cursor"><a>\uFEFF</a>d{I}</span>
   optimize(context?: unknown) {
+    // @ts-expect-error Fix me later
     super.optimize(context);
 
     let { parent } = this;

blots/embed.ts

@@ -57,6 +57,7 @@ class Embed extends EmbedBlot {
         };
       } else {
         textNode = document.createTextNode(text);
+        // @ts-expect-error Fix me later
         this.parent.insertBefore(this.scroll.create(textNode), this.next);
         range = {
           startNode: textNode,

blots/scroll.ts

@@ -83,7 +83,9 @@ class Scroll extends ScrollBlot {
       }
       const ref =
         last.children.head instanceof Break ? null : last.children.head;
+      // @ts-expect-error
       first.moveChildren(last, ref);
+      // @ts-expect-error
       first.remove();
     }
     this.optimize();
@@ -162,7 +164,7 @@ class Scroll extends ScrollBlot {
       blotIndex: number,
       blotLength: number,
     ) => {
-      let lines = [];
+      let lines: (Block | BlockEmbed)[] = [];
       let lengthLeft = blotLength;
       blot.children.forEachAt(
         blotIndex,
@@ -181,7 +183,7 @@ class Scroll extends ScrollBlot {
     return getLines(this, index, length);
   }
 
-  optimize(context: { [key: string]: any }): void;
+  optimize(context?: { [key: string]: any }): void;
   optimize(
     mutations?: MutationRecord[],
     context?: { [key: string]: any },

core/editor.ts

@@ -12,6 +12,11 @@ import { Range } from './selection';
 
 const ASCII = /^[ -~]*$/;
 
+type SelectionInfo = {
+  newRange: Range;
+  oldRange: Range;
+};
+
 class Editor {
   scroll: Scroll;
   delta: Delta;
@@ -158,8 +163,8 @@ class Editor {
   }
 
   getFormat(index: number, length = 0): Record<string, unknown> {
-    let lines = [];
-    let leaves = [];
+    let lines: (Block | BlockEmbed)[] = [];
+    let leaves: LeafBlot[] = [];
     if (length === 0) {
       this.scroll.path(index).forEach(path => {
         const [blot] = path;
@@ -189,10 +194,13 @@ class Editor {
 
   getHTML(index: number, length: number): string {
     const [line, lineOffset] = this.scroll.line(index);
-    if (line.length() >= lineOffset + length) {
-      return convertHTML(line, lineOffset, length, true);
+    if (line) {
+      if (line.length() >= lineOffset + length) {
+        return convertHTML(line, lineOffset, length, true);
+      }
+      return convertHTML(this.scroll, index, length, true);
     }
-    return convertHTML(this.scroll, index, length, true);
+    return '';
   }
 
   getText(index: number, length: number): string {
@@ -226,7 +234,7 @@ class Editor {
     if (this.scroll.children.length === 0) return true;
     if (this.scroll.children.length > 1) return false;
     const blot = this.scroll.children.head;
-    if (blot.statics.blotName !== Block.blotName) return false;
+    if (blot?.statics.blotName !== Block.blotName) return false;
     const block = blot as Block;
     if (block.children.length > 1) return false;
     return block.children.head instanceof Break;
@@ -250,18 +258,25 @@ class Editor {
     return this.applyDelta(delta);
   }
 
-  update(change: Delta, mutations = [], selectionInfo = undefined): Delta {
+  update(
+    change: Delta | null,
+    mutations: MutationRecord[] = [],
+    selectionInfo: SelectionInfo | undefined = undefined,
+  ): Delta {
     const oldDelta = this.delta;
     if (
       mutations.length === 1 &&
       mutations[0].type === 'characterData' &&
+      // @ts-expect-error Fix me later
       mutations[0].target.data.match(ASCII) &&
       this.scroll.find(mutations[0].target)
     ) {
       // Optimization for character changes
       const textBlot = this.scroll.find(mutations[0].target);
       const formats = bubbleFormats(textBlot);
+      // @ts-expect-error Fix me later
       const index = textBlot.offset(this.scroll);
+      // @ts-expect-error Fix me later
       const oldValue = mutations[0].oldValue.replace(CursorBlot.CONTENTS, '');
       const oldText = new Delta().insert(oldValue);
       // @ts-expect-error
@@ -333,7 +348,7 @@ function convertHTML(blot, index, length, isRoot = false) {
   if (blot.children) {
     // TODO fix API
     if (blot.statics.blotName === 'list-container') {
-      const items = [];
+      const items: any[] = [];
       blot.children.forEachAt(index, length, (child, offset, childLength) => {
         const formats = child.formats();
         items.push({
@@ -346,7 +361,7 @@ function convertHTML(blot, index, length, isRoot = false) {
       });
       return convertListHTML(items, -1, []);
     }
-    const parts = [];
+    const parts: string[] = [];
     blot.children.forEachAt(index, length, (child, offset, childLength) => {
       parts.push(convertHTML(child, offset, childLength));
     });
@@ -405,10 +420,7 @@ function normalizeDelta(delta: Delta) {
   }, new Delta());
 }
 
-function shiftRange(
-  { index, length }: { index: number; length: number },
-  amount: number,
-) {
+function shiftRange({ index, length }: Range, amount: number) {
   return new Range(index + amount, length);
 }
 

core/logger.ts

@@ -1,20 +1,25 @@
-const levels = ['error', 'warn', 'log', 'info'];
-let level = 'warn';
+const levels = ['error', 'warn', 'log', 'info'] as const;
+export type DebugLevel = typeof levels[number];
+let level: DebugLevel | false = 'warn';
 
-function debug(method: string, ...args: unknown[]) {
-  if (levels.indexOf(method) <= levels.indexOf(level)) {
-    console[method](...args); // eslint-disable-line no-console
+function debug(method: DebugLevel, ...args: unknown[]) {
+  if (level) {
+    if (levels.indexOf(method) <= levels.indexOf(level)) {
+      console[method](...args); // eslint-disable-line no-console
+    }
   }
 }
 
-function namespace(ns: string): Record<typeof levels[number], typeof debug> {
+function namespace(
+  ns: string,
+): Record<DebugLevel, (...args: unknown[]) => void> {
   return levels.reduce((logger, method) => {
     logger[method] = debug.bind(console, method, ns);
     return logger;
-  }, {});
+  }, {} as Record<DebugLevel, (...args: unknown[]) => void>);
 }
 
-namespace.level = newLevel => {
+namespace.level = (newLevel: DebugLevel | false) => {
   level = newLevel;
 };
 debug.level = namespace.level;

core/quill.ts

@@ -15,7 +15,7 @@ import Uploader from '../modules/uploader';
 import Editor from './editor';
 import Emitter, { EmitterSource } from './emitter';
 import instances from './instances';
-import logger from './logger';
+import logger, { DebugLevel } from './logger';
 import Module from './module';
 import Selection, { Range } from './selection';
 import Theme, { ThemeConstructor } from './theme';
@@ -27,7 +27,7 @@ Parchment.ParentBlot.uiClass = 'ql-ui';
 
 interface Options {
   theme?: string;
-  debug?: string | boolean;
+  debug?: DebugLevel | boolean;
   registry?: Parchment.Registry;
   readOnly?: boolean;
   container?: HTMLElement | string;
@@ -69,7 +69,7 @@ class Quill {
     'core/theme': Theme,
   };
 
-  static debug(limit: string | boolean) {
+  static debug(limit: DebugLevel | boolean) {
     if (limit === true) {
       limit = 'log';
     }
@@ -231,11 +231,11 @@ class Quill {
     this.allowReadOnlyEdits = false;
   }
 
-  addContainer(container: string, refNode?: Node): HTMLDivElement;
-  addContainer(container: HTMLElement, refNode?: Node): HTMLElement;
+  addContainer(container: string, refNode?: Node | null): HTMLDivElement;
+  addContainer(container: HTMLElement, refNode?: Node | null): HTMLElement;
   addContainer(
     container: string | HTMLElement,
-    refNode = null,
+    refNode: Node | null = null,
   ): HTMLDivElement | HTMLElement {
     if (typeof container === 'string') {
       const className = container;
@@ -875,6 +875,7 @@ function overload(
   }
   // Handle format being object, two format name/value strings or excluded
   if (typeof name === 'object') {
+    // @ts-expect-error Fix me later
     formats = name;
     // @ts-expect-error
     source = value;

core/selection.ts

@@ -148,6 +148,7 @@ class Selection {
       // TODO Give blot ability to not split
       if (blot instanceof LeafBlot) {
         const after = blot.split(nativeRange.start.offset);
+        // @ts-expect-error Fix me later
         blot.parent.insertBefore(this.cursor, after);
       } else {
         // @ts-expect-error TODO: nativeRange.start.node doesn't seem to match function signature
@@ -253,13 +254,15 @@ class Selection {
     const indexes = positions.map(position => {
       const [node, offset] = position;
       const blot = this.scroll.find(node, true);
+      // @ts-expect-error Fix me later
       const index = blot.offset(this.scroll);
       if (offset === 0) {
         return index;
       }
       if (blot instanceof LeafBlot) {
         return index + blot.index(node, offset);
       }
+      // @ts-expect-error Fix me later
       return index + blot.length();
     });
     const end = Math.min(Math.max(...indexes), this.scroll.length() - 1);
@@ -289,6 +292,7 @@ class Selection {
           node = node.childNodes[offset];
           offset = 0;
         } else if (node.childNodes.length === offset) {
+          // @ts-expect-error Fix me later
           node = node.lastChild;
           if (node instanceof Text) {
             offset = node.data.length;
@@ -351,6 +355,7 @@ class Selection {
       startNode != null &&
       (this.root.parentNode == null ||
         startNode.parentNode == null ||
+        // @ts-expect-error Fix me later
         endNode.parentNode == null)
     ) {
       return;
@@ -369,19 +374,23 @@ class Selection {
         endOffset !== native.endOffset
       ) {
         if (startNode instanceof Element && startNode.tagName === 'BR') {
+          // @ts-expect-error Fix me later
           startOffset = Array.from(startNode.parentNode.childNodes).indexOf(
             startNode,
           );
           startNode = startNode.parentNode;
         }
         if (endNode instanceof Element && endNode.tagName === 'BR') {
+          // @ts-expect-error Fix me later
           endOffset = Array.from(endNode.parentNode.childNodes).indexOf(
             endNode,
           );
           endNode = endNode.parentNode;
         }
         const range = document.createRange();
+        // @ts-expect-error Fix me later
         range.setStart(startNode, startOffset);
+        // @ts-expect-error Fix me later
         range.setEnd(endNode, endOffset);
         selection.removeAllRanges();
         selection.addRange(range);

e2e/utils/index.ts

@@ -1,8 +1,11 @@
 export const SHORTKEY = process.platform === 'darwin' ? 'Meta' : 'Control';
 
 export function getSelectionInTextNode() {
-  const { anchorNode, anchorOffset, focusNode, focusOffset } =
-    document.getSelection();
+  const selection = document.getSelection();
+  if (!selection) {
+    throw new Error('Selection is null');
+  }
+  const { anchorNode, anchorOffset, focusNode, focusOffset } = selection;
   return JSON.stringify([
     (anchorNode as Text).data,
     anchorOffset,

formats/table.ts

@@ -65,10 +65,15 @@ class TableRow extends Container {
   next: this | null;
 
   checkMerge() {
+    // @ts-expect-error
     if (super.checkMerge() && this.next.children.head != null) {
+      // @ts-expect-error
       const thisHead = this.children.head.formats();
+      // @ts-expect-error
       const thisTail = this.children.tail.formats();
+      // @ts-expect-error
       const nextHead = this.next.children.head.formats();
+      // @ts-expect-error
       const nextTail = this.next.children.tail.formats();
       return (
         thisHead.table === thisTail.table &&
@@ -168,6 +173,7 @@ class TableContainer extends Container {
     if (body == null || body.children.head == null) return;
     body.children.forEach(row => {
       const ref = row.children.at(index);
+      // @ts-expect-error
       const value = TableCell.formats(row.children.head.domNode);
       const cell = this.scroll.create(TableCell.blotName, value);
       row.insertBefore(cell, ref);