Refactor types to use ConstructNameMap interface

Author: wooorm

Diff for: complex-types.d.ts

@@ -3,11 +3,44 @@ import type {Literal} from 'mdast'
 declare module 'mdast-util-from-markdown' {
   // eslint-disable-next-line @typescript-eslint/consistent-type-definitions
   interface CompileData {
-    // Register a new field.
+    /**
+     * Whether we’re in math (flow).
+     */
     mathFlowInside?: boolean | undefined
   }
 }
 
+declare module 'mdast-util-to-markdown' {
+  // eslint-disable-next-line @typescript-eslint/consistent-type-definitions
+  interface ConstructNameMap {
+    /**
+     * Math (flow).
+     *
+     * ```markdown
+     * > | $$
+     *     ^^
+     * > | a
+     *     ^
+     * > | $$
+     *     ^^
+     * ```
+     */
+    mathFlow: 'mathFlow'
+
+    /**
+     * Math (flow) meta flag.
+     *
+     * ```markdown
+     * > | $$a
+     *       ^
+     *   | b
+     *   | $$
+     * ```
+     */
+    mathFlowMeta: 'mathFlowMeta'
+  }
+}
+
 // eslint-disable-next-line @typescript-eslint/consistent-type-definitions
 export interface Math extends Literal {
   type: 'math'

Diff for: index.js

@@ -158,11 +158,8 @@ export function mathToMarkdown(options = {}) {
 
   return {
     unsafe: [
-      // @ts-expect-error: To do: use context map.
       {character: '\r', inConstruct: ['mathFlowMeta']},
-      // @ts-expect-error: To do: use context map.
       {character: '\r', inConstruct: ['mathFlowMeta']},
-      // @ts-expect-error: To do: use context map.
       single
         ? {character: '$', inConstruct: ['mathFlowMeta', 'phrasing']}
         : {
@@ -182,13 +179,11 @@ export function mathToMarkdown(options = {}) {
   function math(node, _, context, safeOptions) {
     const raw = node.value || ''
     const sequence = '$'.repeat(Math.max(longestStreak(raw, '$') + 1, 2))
-    // @ts-expect-error: To do: use context map.
     const exit = context.enter('mathFlow')
     const tracker = track(safeOptions)
     let value = tracker.move(sequence)
 
     if (node.meta) {
-      // @ts-expect-error: To do: use context map.
       const subexit = context.enter('mathFlowMeta')
       value += tracker.move(
         safe(context, node.meta, {