.editorconfig

@@ -1,9 +1,9 @@
 root = true
 
 [*]
-indent_style = space
-indent_size = 2
-end_of_line = lf
 charset = utf-8
-trim_trailing_whitespace = true
+end_of_line = lf
+indent_size = 2
+indent_style = space
 insert_final_newline = true
+trim_trailing_whitespace = true

.github/workflows/bb.yml

@@ -1,13 +1,13 @@
-name: bb
-on:
-  issues:
-    types: [opened, reopened, edited, closed, labeled, unlabeled]
-  pull_request:
-    types: [opened, reopened, edited, closed, labeled, unlabeled]
 jobs:
   main:
     runs-on: ubuntu-latest
     steps:
       - uses: unifiedjs/beep-boop-beta@main
         with:
           repo-token: ${{secrets.GITHUB_TOKEN}}
+name: bb
+on:
+  issues:
+    types: [closed, edited, labeled, opened, reopened, unlabeled]
+  pull_request_target:
+    types: [closed, edited, labeled, opened, reopened, unlabeled]

.github/workflows/main.yml

@@ -1,21 +1,21 @@
-name: main
-on:
-  - pull_request
-  - push
 jobs:
   main:
     name: ${{matrix.node}}
     runs-on: ubuntu-latest
     steps:
-      - uses: actions/checkout@v2
-      - uses: dcodeIO/setup-node-nvm@master
+      - uses: actions/checkout@v4
+      - uses: actions/setup-node@v4
         with:
           node-version: ${{matrix.node}}
       - run: npm install
       - run: npm test
-      - uses: codecov/codecov-action@v1
+      - uses: codecov/codecov-action@v5
     strategy:
       matrix:
         node:
-          - lts/erbium
+          - lts/hydrogen
           - node
+name: main
+on:
+  - pull_request
+  - push

.gitignore

@@ -1,6 +1,8 @@
-.DS_Store
 *.d.ts
 *.log
+*.map
+*.tsbuildinfo
+.DS_Store
 coverage/
 node_modules/
 yarn.lock

.npmrc

@@ -1 +1,2 @@
+ignore-scripts=true
 package-lock=false

index.js

@@ -1,58 +1 @@
-/**
- * @typedef {import('unist').Node} Node
- * @typedef {import('unist').Parent} Parent
- *
- * @typedef {import('unist-util-is').Type} Type
- * @typedef {import('unist-util-is').Props} Props
- * @typedef {import('unist-util-is').TestFunctionAnything} TestFunctionAnything
- */
-
-import {convert} from 'unist-util-is'
-
-export var findBefore =
-  /**
-   * @type {(
-   *  (<T extends Node>(node: Parent, index: Node|number, test: T['type']|Partial<T>|import('unist-util-is').TestFunctionPredicate<T>|Array.<T['type']|Partial<T>|import('unist-util-is').TestFunctionPredicate<T>>) => T|null) &
-   *  ((node: Parent, index: Node|number, test?: null|undefined|Type|Props|TestFunctionAnything|Array<Type|Props|TestFunctionAnything>) => Node|null)
-   * )}
-   */
-  (
-    /**
-     * @param {Parent} parent Parent node
-     * @param {Node|number} index Child of `parent`, or it’s index
-     * @param {null|undefined|Type|Props|TestFunctionAnything|Array<Type|Props|TestFunctionAnything>} [test] is-compatible test (such as a type)
-     * @returns {Node|null}
-     */
-    function (parent, index, test) {
-      var is = convert(test)
-
-      if (!parent || !parent.type || !parent.children) {
-        throw new Error('Expected parent node')
-      }
-
-      if (typeof index === 'number') {
-        if (index < 0 || index === Number.POSITIVE_INFINITY) {
-          throw new Error('Expected positive finite number as index')
-        }
-      } else {
-        index = parent.children.indexOf(index)
-
-        if (index < 0) {
-          throw new Error('Expected child node or index')
-        }
-      }
-
-      // Performance.
-      if (index > parent.children.length) {
-        index = parent.children.length
-      }
-
-      while (index--) {
-        if (is(parent.children[index], index, parent)) {
-          return parent.children[index]
-        }
-      }
-
-      return null
-    }
-  )
+export {findBefore} from './lib/index.js'

index.test-d.ts

@@ -0,0 +1,42 @@
+import {expectType} from 'tsd'
+import type {
+  Heading,
+  PhrasingContent,
+  Root,
+  RootContent,
+  RowContent,
+  TableCell,
+  TableRow,
+  Text
+} from 'mdast'
+import {findBefore} from './index.js'
+
+const text: Text = {type: 'text', value: 'alpha'}
+const heading: Heading = {type: 'heading', depth: 1, children: [text]}
+const root: Root = {type: 'root', children: [heading]}
+const cell: TableCell = {type: 'tableCell', children: [text]}
+const row: TableRow = {type: 'tableRow', children: [cell]}
+
+// @ts-expect-error: parent needed.
+findBefore()
+
+// @ts-expect-error: child or index needed.
+findBefore(heading)
+
+findBefore(
+  // @ts-expect-error: parent needed.
+  text,
+  0
+)
+
+expectType<PhrasingContent | undefined>(findBefore(heading, text))
+
+expectType<Text | undefined>(findBefore(heading, text, 'text'))
+
+expectType<Text | undefined>(findBefore(heading, 0, 'text'))
+
+expectType<RootContent | undefined>(findBefore(root, 0))
+
+expectType<Text | undefined>(findBefore(root, 0, 'text'))
+
+expectType<RowContent | undefined>(findBefore(row, 0))

lib/index.js

@@ -0,0 +1,132 @@
+/**
+ * @import {Test} from 'unist-util-is'
+ * @import {Node as UnistNode, Parent as UnistParent} from 'unist'
+ */
+
+/**
+ * @typedef {(
+ *   Fn extends (value: any) => value is infer Thing
+ *   ? Thing
+ *   : Fallback
+ * )} Predicate
+ *   Get the value of a type guard `Fn`.
+ * @template Fn
+ *   Value; typically function that is a type guard (such as `(x): x is Y`).
+ * @template Fallback
+ *   Value to yield if `Fn` is not a type guard.
+ */
+
+/**
+ * @typedef {(
+ *   Check extends null | undefined // No test.
+ *   ? Value
+ *   : Value extends {type: Check} // String (type) test.
+ *   ? Value
+ *   : Value extends Check // Partial test.
+ *   ? Value
+ *   : Check extends Function // Function test.
+ *   ? Predicate<Check, Value> extends Value
+ *     ? Predicate<Check, Value>
+ *     : never
+ *   : never // Some other test?
+ * )} MatchesOne
+ *   Check whether a node matches a primitive check in the type system.
+ * @template Value
+ *   Value; typically unist `Node`.
+ * @template Check
+ *   Value; typically `unist-util-is`-compatible test, but not arrays.
+ */
+
+/**
+ * @typedef {(
+ *   Check extends Array<any>
+ *   ? MatchesOne<Value, Check[keyof Check]>
+ *   : MatchesOne<Value, Check>
+ * )} Matches
+ *   Check whether a node matches a check in the type system.
+ * @template Value
+ *   Value; typically unist `Node`.
+ * @template Check
+ *   Value; typically `unist-util-is`-compatible test.
+ */
+
+/**
+ * @typedef {(
+ *   Kind extends {children: Array<infer Child>}
+ *   ? Child
+ *   : never
+ * )} Child
+ *   Collect nodes that can be parents of `Child`.
+ * @template {UnistNode} Kind
+ *   All node types.
+ */
+
+import {convert} from 'unist-util-is'
+
+/**
+ * Find the first node in `parent` before another `node` or before an index,
+ * that passes `test`.
+ *
+ * @param parent
+ *   Parent node.
+ * @param index
+ *   Child node or index.
+ * @param [test=undefined]
+ *   Test for child to look for (optional).
+ * @returns
+ *   A child (matching `test`, if given) or `undefined`.
+ */
+export const findBefore =
+  // Note: overloads like this are needed to support optional generics.
+  /**
+   * @type {(
+   *   (<Kind extends UnistParent, Check extends Test>(parent: Kind, index: Child<Kind> | number, test: Check) => Matches<Child<Kind>, Check> | undefined) &
+   *   (<Kind extends UnistParent>(parent: Kind, index: Child<Kind> | number, test?: null | undefined) => Child<Kind> | undefined)
+   * )}
+   */
+  (
+    /**
+     * @param {UnistParent} parent
+     *   Parent node.
+     * @param {UnistNode | number} index
+     *   Child node or index.
+     * @param {Test} [test=undefined]
+     *   Test for child to look for.
+     * @returns {UnistNode | undefined}
+     *   A child (matching `test`, if given) or `undefined`.
+     */
+    function (parent, index, test) {
+      const is = convert(test)
+
+      if (!parent || !parent.type || !parent.children) {
+        throw new Error('Expected parent node')
+      }
+
+      if (typeof index === 'number') {
+        if (index < 0 || index === Number.POSITIVE_INFINITY) {
+          throw new Error('Expected positive finite number as index')
+        }
+      } else {
+        index = parent.children.indexOf(index)
+
+        if (index < 0) {
+          throw new Error('Expected child node or index')
+        }
+      }
+
+      // Performance.
+      if (index > parent.children.length) {
+        index = parent.children.length
+      }
+
+      while (index--) {
+        const child = parent.children[index]
+
+        if (is(child, index, parent)) {
+          return child
+        }
+      }
+
+      return undefined
+    }
+  )

license

@@ -1,6 +1,6 @@
 (The MIT License)
 
-Copyright (c) 2015 Titus Wormer <tituswormer@gmail.com>
+Copyright (c) Titus Wormer <tituswormer@gmail.com>
 
 Permission is hereby granted, free of charge, to any person obtaining
 a copy of this software and associated documentation files (the