[babel 8] type checking preset-flow options (#12751)

Co-authored-by: Nicolò Ribaudo <nicolo.ribaudo@gmail.com>

packages/babel-preset-flow/package.json

@@ -21,6 +21,7 @@
   ],
   "dependencies": {
     "@babel/helper-plugin-utils": "workspace:^7.12.13",
+    "@babel/helper-validator-option": "workspace:^7.12.11",
     "@babel/plugin-transform-flow-strip-types": "workspace:^7.12.13"
   },
   "peerDependencies": {

packages/babel-preset-flow/src/index.js

@@ -1,8 +1,10 @@
 import { declare } from "@babel/helper-plugin-utils";
 import transformFlowStripTypes from "@babel/plugin-transform-flow-strip-types";
+import normalizeOptions from "./normalize-options";
 
-export default declare((api, { all, allowDeclareFields }) => {
+export default declare((api, opts) => {
   api.assertVersion(7);
+  const { all, allowDeclareFields } = normalizeOptions(opts);
 
   return {
     plugins: [[transformFlowStripTypes, { all, allowDeclareFields }]],

packages/babel-preset-flow/src/normalize-options.js

@@ -0,0 +1,25 @@
+import { OptionValidator } from "@babel/helper-validator-option";
+const v = new OptionValidator("@babel/preset-flow");
+
+export default function normalizeOptions(options = {}) {
+  let { all } = options;
+  const { allowDeclareFields } = options;
+
+  if (process.env.BABEL_8_BREAKING) {
+    v.invariant(
+      !("allowDeclareFields" in options),
+      `Since Babel 8, \`declare property: A\` is always supported, and the "allowDeclareFields" option is no longer available. Please remove it from your config.`,
+    );
+    const TopLevelOptions = {
+      all: "all",
+    };
+    v.validateTopLevelOptions(options, TopLevelOptions);
+    all = v.validateBooleanOption(TopLevelOptions.all, options.all);
+    return { all };
+  } else {
+    return {
+      all,
+      allowDeclareFields,
+    };
+  }
+}

packages/babel-preset-flow/test/normalize-options.spec.js

@@ -0,0 +1,55 @@
+import normalizeOptions from "../src/normalize-options";
+describe("normalize options", () => {
+  (process.env.BABEL_8_BREAKING ? describe : describe.skip)("Babel 8", () => {
+    it("should throw on unknown options", () => {
+      expect(() => normalizeOptions({ al: true }))
+        .toThrowErrorMatchingInlineSnapshot(`
+        "@babel/preset-flow: 'al' is not a valid top-level option.
+        - Did you mean 'all'?"
+      `);
+    });
+    it("should throw on Babel 7 `allowDeclareFields` option", () => {
+      expect(() =>
+        normalizeOptions({ allowDeclareFields: true }),
+      ).toThrowErrorMatchingInlineSnapshot(
+        `"@babel/preset-flow: Since Babel 8, \`declare property: A\` is always supported, and the \\"allowDeclareFields\\" option is no longer available. Please remove it from your config."`,
+      );
+    });
+    it.each(["all"])("should throw when `%p` is not a boolean", optionName => {
+      expect(() => normalizeOptions({ [optionName]: 0 })).toThrow(
+        `@babel/preset-flow: '${optionName}' option must be a boolean.`,
+      );
+    });
+    it("should not throw when options is not defined", () => {
+      expect(() => normalizeOptions()).not.toThrowError();
+    });
+    it("default values", () => {
+      expect(normalizeOptions({})).toMatchInlineSnapshot(`
+        Object {
+          "all": undefined,
+        }
+      `);
+    });
+  });
+  (process.env.BABEL_8_BREAKING ? describe.skip : describe)("Babel 7", () => {
+    it("should not throw on unknown options", () => {
+      expect(() =>
+        normalizeOptions({ allDeclareField: true }),
+      ).not.toThrowError();
+    });
+    it.each(["all", "allowDeclareFields"])(
+      "should not throw when `%p` is not a boolean",
+      optionName => {
+        expect(() => normalizeOptions({ [optionName]: 0 })).not.toThrowError();
+      },
+    );
+    it("default values", () => {
+      expect(normalizeOptions({})).toMatchInlineSnapshot(`
+        Object {
+          "all": undefined,
+          "allowDeclareFields": undefined,
+        }
+      `);
+    });
+  });
+});

yarn.lock

@@ -851,7 +851,7 @@ __metadata:
   languageName: node
   linkType: hard
 
-"@babel/helper-validator-option@workspace:^7.12.17, @babel/helper-validator-option@workspace:packages/babel-helper-validator-option":
+"@babel/helper-validator-option@workspace:^7.12.11, @babel/helper-validator-option@workspace:^7.12.17, @babel/helper-validator-option@workspace:packages/babel-helper-validator-option":
   version: 0.0.0-use.local
   resolution: "@babel/helper-validator-option@workspace:packages/babel-helper-validator-option"
   languageName: unknown
@@ -3169,6 +3169,7 @@ __metadata:
     "@babel/core": "workspace:*"
     "@babel/helper-plugin-test-runner": "workspace:*"
     "@babel/helper-plugin-utils": "workspace:^7.12.13"
+    "@babel/helper-validator-option": "workspace:^7.12.11"
     "@babel/plugin-transform-flow-strip-types": "workspace:^7.12.13"
   peerDependencies:
     "@babel/core": ^7.0.0-0