add logic to sass rule conditional on sass-loader version

__mocks__/nonexistent/package.json

@@ -0,0 +1,4 @@
+{
+ "main": "./wat",
+ "version": "12.0.0"
+}

__mocks__/sass-loader/package.json

@@ -0,0 +1,4 @@
+{
+ "main": "./lib/api.js",
+ "version": "16.56.81"
+}

jest.config.js

@@ -1,4 +1,5 @@
 module.exports = {
  roots: ["<rootDir>/test"],
- testPathIgnorePatterns: ["/__fixtures__/", "/__utils__/"]
+ testPathIgnorePatterns: ["/__fixtures__/", "/__utils__/"],
+ resolver: "<rootDir>/test/resolver"
 }

package/rules/sass.js

@@ -1,16 +1,18 @@
 /* eslint global-require: 0 */
 
 const getStyleRule = require("../utils/getStyleRule")
-const { canProcess } = require("../utils/helpers")
-const { additional_paths: includePaths } = require("../config")
+const { canProcess, packageMajorVersion } = require("../utils/helpers")
+const { additional_paths: extraPaths } = require("../config")
 
-module.exports = canProcess("sass-loader", (resolvedPath) =>
- getStyleRule(/\.(scss|sass)(\.erb)?$/i, [
+module.exports = canProcess("sass-loader", (resolvedPath) => {
+ const optionKey =
+ packageMajorVersion("sass-loader") > 15 ? "loadPaths" : "includePaths"
+ return getStyleRule(/\.(scss|sass)(\.erb)?$/i, [
  {
  loader: resolvedPath,
  options: {
- sassOptions: { includePaths }
+ sassOptions: { [optionKey]: extraPaths }
  }
  }
  ])
-)
+})

package/utils/helpers.js

@@ -41,10 +41,18 @@ const loaderMatches = (configLoader, loaderToCheck, fn) => {
  return fn()
 }
 
+const packageMajorVersion = (packageName) => {
+ // eslint-disable-next-line import/no-dynamic-require
+ const packageJsonPath = require.resolve(`${packageName}/package.json`)
+ // eslint-disable-next-line import/no-dynamic-require, global-require
+ return require(packageJsonPath).version.match(/^\d+/)[0]
+}
+
 module.exports = {
  isBoolean,
  ensureTrailingSlash,
  canProcess,
  moduleExists,
- loaderMatches
+ loaderMatches,
+ packageMajorVersion
 }

test/package/helpers.test.js

@@ -0,0 +1,11 @@
+const { packageMajorVersion } = require("../../package/utils/helpers")
+
+describe("packageMajorVersion", () => {
+ test("should find that sass-loader is v16", () => {
+ expect(packageMajorVersion("sass-loader")).toBe("16")
+ })
+
+ test("should find that nonexistent is v12", () => {
+ expect(packageMajorVersion("nonexistent")).toBe("12")
+ })
+})

test/package/rules/sass.test.js

@@ -0,0 +1,25 @@
+const sass = require("../../../package/rules/sass")
+
+jest.mock("../../../package/utils/helpers", () => {
+ const original = jest.requireActual("../../../package/utils/helpers")
+ const canProcess = (rule, fn) => {
+ return fn("This path was mocked")
+ }
+ const moduleExists = () => true
+ const packageMajorVersion = () => "15"
+ return {
+ ...original,
+ canProcess,
+ moduleExists,
+ packageMajorVersion
+ }
+})
+
+jest.mock("../../../package/utils/inliningCss", () => true)
+
+describe("sass rule", () => {
+ test("contains loadPaths as the sassOptions key if sass-loader is v15 or earlier", () => {
+ expect(typeof sass.use[3].options.sassOptions.includePaths).toBe("object")
+ expect(typeof sass.use[3].options.sassOptions.loadPaths).toBe("undefined")
+ })
+})

test/package/rules/sass1.test.js

@@ -0,0 +1,25 @@
+const sass = require("../../../package/rules/sass")
+
+jest.mock("../../../package/utils/helpers", () => {
+ const original = jest.requireActual("../../../package/utils/helpers")
+ const canProcess = (rule, fn) => {
+ return fn("This path was mocked")
+ }
+ const moduleExists = () => true
+ return {
+ ...original,
+ canProcess,
+ moduleExists
+ }
+})
+
+jest.mock("../../../package/utils/inliningCss", () => true)
+
+describe("sass rule", () => {
+ test("contains loadPaths as the sassOptions key if sass-loader is v15 or earlier", () => {
+ expect(typeof sass.use[3].options.sassOptions.includePaths).toBe(
+ "undefined"
+ )
+ expect(typeof sass.use[3].options.sassOptions.loadPaths).toBe("object")
+ })
+})

test/resolver.js

@@ -0,0 +1,13 @@
+const mapping = {
+ "css-loader": "this path was mocked",
+ "sass-loader/package.json": "../../__mocks__/sass-loader/package.json",
+ "nonexistent/package.json": "../../__mocks__/nonexistent/package.json"
+}
+
+function resolver(module, options) {
+ // If the path corresponds to a key in the mapping object, returns the fakely resolved path
+ // otherwise it calls the Jest's default resolver
+ return mapping[module] || options.defaultResolver(module, options)
+}
+
+module.exports = resolver