fix(gatsby): use file:// protocol when importing gatsby-config/node

packages/gatsby/src/bootstrap/get-config-file.ts

@@ -4,7 +4,7 @@ import report from "gatsby-cli/lib/reporter"
 import path from "path"
 import { COMPILED_CACHE_DIR } from "../utils/parcel/compile-gatsby-files"
 import { isNearMatch } from "../utils/is-near-match"
-import { resolveJSFilepath } from "./resolve-js-file-path"
+import { resolveJSFilepath, maybeAddFileProtocol } from "./resolve-js-file-path"
 import { preferDefault } from "./prefer-default"
 
 export async function getConfigFile(
@@ -47,7 +47,7 @@ async function attemptImport(
     return { configFilePath: ``, configModule: undefined }
   }
 
-  const importedModule = await import(configFilePath)
+  const importedModule = await import(maybeAddFileProtocol(configFilePath))
   const configModule = preferDefault(importedModule)
 
   return { configFilePath, configModule }

packages/gatsby/src/bootstrap/load-plugins/__tests__/load-plugins.ts

@@ -33,6 +33,7 @@ jest.mock(`../../resolve-js-file-path`, () => {
     resolveJSFilepath: jest.fn(
       ({ filePath }) => `${filePath.replace(`src`, `dist`)}.js`
     ),
+    maybeAddFileProtocol: jest.fn(val => val),
   }
 })
 

packages/gatsby/src/bootstrap/resolve-js-file-path.ts

@@ -1,6 +1,16 @@
 import path from "path"
+import { pathToFileURL } from "url"
 import report from "gatsby-cli/lib/reporter"
 
+/**
+ * On Windows, the file protocol is required for the path to be resolved correctly.
+ * On other platforms, the file protocol is not required, but supported, so we want to just always use it.
+ * Except jest doesn't work with that and in that environment we never add the file protocol.
+ */
+export const maybeAddFileProtocol = process.env.JEST_WORKER_ID
+  ? (module: string): string => module
+  : (module: string): string => pathToFileURL(module).href
+
 /**
  * Figure out if the file path is .js or .mjs without relying on the fs module, and return the file path if it exists.
  */

packages/gatsby/src/bootstrap/resolve-module-exports.ts

@@ -6,7 +6,7 @@ import report from "gatsby-cli/lib/reporter"
 import { babelParseToAst } from "../utils/babel-parse-to-ast"
 import { testImportError } from "../utils/test-import-error"
 import { resolveModule, ModuleResolver } from "../utils/module-resolver"
-import { resolveJSFilepath } from "./resolve-js-file-path"
+import { maybeAddFileProtocol, resolveJSFilepath } from "./resolve-js-file-path"
 import { preferDefault } from "./prefer-default"
 
 const staticallyAnalyzeExports = (
@@ -215,7 +215,9 @@ export async function resolveModuleExports(
         return []
       }
 
-      const rawImportedModule = await import(moduleFilePath)
+      const rawImportedModule = await import(
+        maybeAddFileProtocol(moduleFilePath)
+      )
 
       // If the module is cjs, the properties we care about are nested under a top-level `default` property
       const importedModule = preferDefault(rawImportedModule)

packages/gatsby/src/utils/import-gatsby-plugin.ts

@@ -1,4 +1,7 @@
-import { resolveJSFilepath } from "../bootstrap/resolve-js-file-path"
+import {
+  resolveJSFilepath,
+  maybeAddFileProtocol,
+} from "../bootstrap/resolve-js-file-path"
 import { preferDefault } from "../bootstrap/prefer-default"
 
 const pluginModuleCache = new Map<string, any>()
@@ -38,7 +41,7 @@ export async function importGatsbyPlugin(
       filePath: importPluginModulePath,
     })
 
-    const rawPluginModule = await import(pluginFilePath)
+    const rawPluginModule = await import(maybeAddFileProtocol(pluginFilePath))
 
     // If the module is cjs, the properties we care about are nested under a top-level `default` property
     pluginModule = preferDefault(rawPluginModule)