refactor(is-file): Convert to TypeScript

packages/gatsby/src/schema/infer/add-inferred-fields.js

@@ -4,7 +4,7 @@ const { GraphQLList } = require(`graphql`)
 const invariant = require(`invariant`)
 const report = require(`gatsby-cli/lib/reporter`)
 
-const { isFile } = require(`./is-file`)
+import { isFile } from "./is-file"
 const { isDate } = require(`../types/date`)
 const { addDerivedType } = require(`../types/derived-types`)
 import { is32BitInteger } from "../../utils/is-32-bit-integer"

packages/gatsby/src/schema/infer/is-file.js → packages/gatsby/src/schema/infer/is-file.ts

@@ -1,33 +1,68 @@
-const path = require(`path`)
-const { slash } = require(`gatsby-core-utils`)
-const mime = require(`mime`)
-const isRelative = require(`is-relative`)
-const isRelativeUrl = require(`is-relative-url`)
+import path from "path"
+import { slash } from "gatsby-core-utils"
+import mime from "mime"
+import isRelative from "is-relative"
+import isRelativeUrl from "is-relative-url"
 import { getValueAt } from "../../utils/get-value-at"
-const { getNode, getNodesByType } = require(`../../redux/nodes`)
+import { getNode, getNodesByType } from "../../redux/nodes"
+import { IGatsbyNode } from "../../redux/types"
 
-const isFile = (fieldPath, relativePath) => {
-  const filePath = getFilePath(fieldPath, relativePath)
-  if (!filePath) return false
-  const filePathExists = getNodesByType(`File`).some(
-    node => node.absolutePath === filePath
-  )
-  return filePathExists
-}
-
-module.exports = {
-  isFile,
-}
-
-const getFirstValueAt = (node, selector) => {
+const getFirstValueAt = (
+  node: IGatsbyNode,
+  selector: string | string[]
+): string => {
   let value = getValueAt(node, selector)
   while (Array.isArray(value)) {
     value = value[0]
   }
   return value
 }
 
-const getFilePath = (fieldPath, relativePath) => {
+const withBaseDir = (dir: string) => (p: string): string =>
+  path.posix.join(dir, slash(p))
+
+const findAncestorNode = (
+  childNode: IGatsbyNode,
+  predicate: (n: IGatsbyNode) => boolean
+): IGatsbyNode | null => {
+  let node: IGatsbyNode | undefined = childNode
+  do {
+    if (predicate(node)) {
+      return node
+    }
+    node = getNode(node.parent)
+  } while (node !== undefined)
+  return null
+}
+
+const getBaseDir = (node: IGatsbyNode): string | null => {
+  if (node) {
+    const { dir } = findAncestorNode(
+      node,
+      node => node.internal.type === `File`
+    ) || { dir: `` }
+    return typeof dir === `string` ? dir : null
+  }
+  return null
+}
+
+const getAbsolutePath = (
+  node: IGatsbyNode,
+  relativePath: string
+): string | string[] | null => {
+  const dir = getBaseDir(node)
+  const withDir = withBaseDir(dir ?? ``)
+  return dir
+    ? Array.isArray(relativePath)
+      ? relativePath.map(withDir)
+      : withDir(relativePath)
+    : null
+}
+
+const getFilePath = (
+  fieldPath: string,
+  relativePath: string
+): string | string[] | null => {
   const [typeName, ...selector] = Array.isArray(fieldPath)
     ? fieldPath
     : fieldPath.split(`.`)
@@ -52,33 +87,11 @@ const getFilePath = (fieldPath, relativePath) => {
   return node ? getAbsolutePath(node, normalizedPath) : null
 }
 
-const getAbsolutePath = (node, relativePath) => {
-  const dir = getBaseDir(node)
-  const withDir = withBaseDir(dir)
-  return dir
-    ? Array.isArray(relativePath)
-      ? relativePath.map(withDir)
-      : withDir(relativePath)
-    : null
-}
-
-const getBaseDir = node => {
-  if (node) {
-    const { dir } =
-      findAncestorNode(node, node => node.internal.type === `File`) || {}
-    return dir
-  }
-  return null
-}
-
-const withBaseDir = dir => p => path.posix.join(dir, slash(p))
-
-const findAncestorNode = (childNode, predicate) => {
-  let node = childNode
-  do {
-    if (predicate(node)) {
-      return node
-    }
-  } while ((node = node.parent && getNode(node.parent)))
-  return null
+export const isFile = (fieldPath: string, relativePath: string): boolean => {
+  const filePath = getFilePath(fieldPath, relativePath)
+  if (!filePath) return false
+  const filePathExists = getNodesByType(`File`).some(
+    node => node.absolutePath === filePath
+  )
+  return filePathExists
 }