diff --git a/lib/index.js b/lib/index.js
index d2b124e..ffa9a0f 100644
--- a/lib/index.js
+++ b/lib/index.js
@@ -7,12 +7,23 @@
  * @typedef {'basename' | 'dirname' | 'extname' | 'path' | 'stem'} Field
  *   Fields related to paths.
  *
- * @typedef SpecAffix
- *   Define prepending and/or appending.
- * @property {string | null | undefined} [prefix]
- *   Substring to prepend in front of the field.
- * @property {string | null | undefined} [suffix]
- *   Substring to append after the field.
+ * @callback Move
+ *   Move.
+ * @param {VFile} file
+ *   File to change.
+ * @returns {undefined}
+ *   Nothing.
+ *
+ * @typedef {Array<Move | Spec | string> | Move | Spec | string} Renames
+ *   Rename instructions.
+ *
+ *   *   if the bound rename is a normal string starting with a dot (`.`), sets
+ *       `file.extname`
+ *   *   otherwise, if the bound rename is a normal string, sets `file.basename`
+ *   *   otherwise, if the bound test is an array, all renames in it are
+ *       performed
+ *   *   otherwise, if the bound rename is an object, renames according to the
+ *       `Spec`
  *
  * @typedef Spec
  *   An object describing path properties to values.
@@ -31,32 +42,15 @@
  *   Change file path (`'~/index.min.js'`).
  * @property {VFileOptions['stem'] | SpecAffix} [stem]
  *   Change stem (`'index.min'`).
- */
-
-/**
- * @callback Move
- *   Move.
- * @param {VFile} file
- *   File to change.
- * @returns {undefined}
- *   Nothing.
- */
-
-/**
- * @typedef {Array<Move | Spec | string> | Move | Spec | string} Renames
- *   Rename instructions.
  *
- *   *   if the bound rename is a normal string starting with a dot (`.`), sets
- *       `file.extname`
- *   *   otherwise, if the bound rename is a normal string, sets `file.basename`
- *   *   otherwise, if the bound test is an array, all renames in it are
- *       performed
- *   *   otherwise, if the bound rename is an object, renames according to the
- *       `Spec`
+ * @typedef SpecAffix
+ *   Define prepending and/or appending.
+ * @property {string | null | undefined} [prefix]
+ *   Substring to prepend in front of the field.
+ * @property {string | null | undefined} [suffix]
+ *   Substring to append after the field.
  */
 
-const own = {}.hasOwnProperty
-
 // Order of renaming properties.
 // See <https://github.com/vfile/vfile/blob/86677e2/lib/index.js#L89>
 // Other properties are invalid.
@@ -68,22 +62,7 @@ const order = /** @type {const} */ ([
   'dirname'
 ])
 
-/**
- * Rename a file.
- *
- * When given something, returns a vfile from that, and changes its path
- * properties.
- *
- * @param {VFile} file
- *   File to rename.
- * @param {Renames | null | undefined} [renames]
- *   Rename instructions.
- * @returns {undefined}
- *   Nothing.
- */
-export function rename(file, renames) {
-  convert(renames)(file)
-}
+const own = {}.hasOwnProperty
 
 /**
  * Create a function (the move) from `renames`, that when given a file changes
@@ -104,77 +83,72 @@ export function convert(renames) {
   }
 
   if (typeof renames === 'string') {
-    return setter(renames.charAt(0) === '.' ? 'extname' : 'basename', renames)
+    return createSetterMove(
+      renames.charAt(0) === '.' ? 'extname' : 'basename',
+      renames
+    )
   }
 
   if (typeof renames === 'object') {
     return Array.isArray(renames)
-      ? allFactory(convertAll(renames))
-      : specFactory(renames)
+      ? createMoves(renames)
+      : createSpecMove(renames)
   }
 
   throw new Error('Expected function, string, array, or object as renames')
 }
 
 /**
- * @param {Spec} spec
+ * Rename a file.
+ *
+ * When given something, returns a vfile from that, and changes its path
+ * properties.
+ *
+ * @param {VFile} file
+ *   File to rename.
+ * @param {Renames | null | undefined} [renames]
+ *   Rename instructions.
+ * @returns {undefined}
+ *   Nothing.
+ */
+export function rename(file, renames) {
+  convert(renames)(file)
+}
+
+/**
+ * Create a move from multiples moves.
+ *
+ * @param {Array<Move>} moves
+ *   Moves.
  * @returns {Move}
+ *   Move.
  */
-function specFactory(spec) {
-  /** @type {Array<Field>} */
-  const props = []
-  /** @type {Array<Move>} */
-  const moves = []
-  /** @type {Field} */
-  let prop
+function combineMoves(moves) {
+  return move
 
-  // Fail on non-path props.
-  for (prop in spec) {
-    if (own.call(spec, prop)) {
-      if (!order.includes(prop)) {
-        throw new Error(
-          'Cannot rename `' + prop + '`: it’s not a path property'
-        )
-      }
+  /** @type {Move} */
+  function move(file) {
+    const history = [...file.history]
+    let index = -1
 
-      props.push(prop)
+    while (++index < moves.length) {
+      moves[index](file)
     }
-  }
-
-  // Create moves for all specs.
-  props.sort(sort)
 
-  let index = -1
-
-  while (++index < props.length) {
-    const prop = props[index]
-    const value = spec[prop]
-
-    if (typeof value === 'string') {
-      moves.push(setter(prop, value))
-    } else if (value) {
-      if ('prefix' in value && value.prefix) {
-        moves.push(prefix(prop, value.prefix))
-      }
-
-      if ('suffix' in value && value.suffix) {
-        moves.push(suffix(prop, value.suffix))
-      }
-    }
+    // Clean history to only include one changed path.
+    file.history = [...history, file.path]
   }
-
-  return allFactory(moves)
 }
 
 /**
- * Convert renames into moves.
+ * Convert renames into a move.
  *
- * @param {Array<string | Move | Spec>} renames
+ * @param {Array<Move | Spec | string>} renames
  *   Renames.
- * @returns {Array<Move>}
- *   Moves.
+ * @returns {Move}
+ *   Move.
  */
-function convertAll(renames) {
+function createMoves(renames) {
   /** @type {Array<Move>} */
   const moves = []
   let index = -1
@@ -183,35 +157,29 @@ function convertAll(renames) {
     moves[index] = convert(renames[index])
   }
 
-  return moves
+  return combineMoves(moves)
 }
 
 /**
- * Create a move from multiples moves.
+ * Create a move that prepends.
  *
- * @param {Array<Move>} changes
- *   Moves.
+ * @param {Field} key
+ *   Field.
+ * @param {string} prefix
+ *   Value to add.
  * @returns {Move}
  *   Move.
  */
-function allFactory(changes) {
-  return all
+function createPrefixMove(key, prefix) {
+  return add
   /** @type {Move} */
-  function all(file) {
-    const history = file.history.concat()
-    let index = -1
-
-    while (++index < changes.length) {
-      changes[index](file)
-    }
-
-    // Clean history to only include one changed path.
-    file.history = [...history, file.path]
+  function add(file) {
+    file[key] = prefix + file[key]
   }
 }
 
 /**
- * Create a move that sets.
+ * Create a move that sets a field.
  *
  * @param {Field} key
  *   Field.
@@ -220,30 +188,67 @@ function allFactory(changes) {
  * @returns {Move}
  *   Move.
  */
-function setter(key, value) {
-  return set
+function createSetterMove(key, value) {
+  return move
+
   /** @type {Move} */
-  function set(file) {
+  function move(file) {
     file[key] = value
   }
 }
 
 /**
- * Create a move that prepends.
+ * Convert a spec into a move.
  *
- * @param {Field} key
- *   Field.
- * @param {string} prefix
- *   Value to add.
+ * @param {Spec} spec
+ *   Spec.
  * @returns {Move}
  *   Move.
  */
-function prefix(key, prefix) {
-  return add
-  /** @type {Move} */
-  function add(file) {
-    file[key] = prefix + file[key]
+function createSpecMove(spec) {
+  /** @type {Array<Field>} */
+  const props = []
+  /** @type {Array<Move>} */
+  const moves = []
+  /** @type {Field} */
+  let prop
+
+  // Fail on non-path props.
+  for (prop in spec) {
+    if (own.call(spec, prop)) {
+      if (!order.includes(prop)) {
+        throw new Error(
+          'Cannot rename `' + prop + '`: it’s not a path property'
+        )
+      }
+
+      props.push(prop)
+    }
+  }
+
+  // Create moves for all specs.
+  props.sort(sort)
+
+  let index = -1
+
+  while (++index < props.length) {
+    const prop = props[index]
+    const value = spec[prop]
+
+    if (typeof value === 'string') {
+      moves.push(createSetterMove(prop, value))
+    } else if (value) {
+      if ('prefix' in value && value.prefix) {
+        moves.push(createPrefixMove(prop, value.prefix))
+      }
+
+      if ('suffix' in value && value.suffix) {
+        moves.push(createSuffixMove(prop, value.suffix))
+      }
+    }
   }
+
+  return combineMoves(moves)
 }
 
 /**
@@ -256,7 +261,7 @@ function prefix(key, prefix) {
  * @returns {Move}
  *   Move.
  */
-function suffix(key, suffix) {
+function createSuffixMove(key, suffix) {
   return add
   /** @type {Move} */
   function add(file) {
diff --git a/readme.md b/readme.md
index 6e563e9..63c181c 100644
--- a/readme.md
+++ b/readme.md
@@ -157,7 +157,7 @@ Rename instructions (TypeScript type).
 ###### Type
 
 ```ts
-type Renames = string | Move | Spec | Array<string | Move | Spec>
+type Renames = Array<Move | Spec | string> | Move | Spec | string
 ```
 
 ### `Spec`