Fix inline-plugin's Platform.select transform when used with ObjectMe…

…thod

Summary:
Previously, metro was transforming `Platform.select` calls with ObjectMethod
properties into `undefined`.

This transforms these properties into named FunctionExpressions instead. I
believe this should preserve the original semantics.

Reviewed By: MichaReiser

Differential Revision: D25719371

fbshipit-source-id: 08473eee851b4e12ea753bc45595acec41363351

packages/metro-transform-plugins/src/__tests__/inline-plugin-test.js

@@ -312,6 +312,46 @@ describe('inline constants', () => {
     });
   });
 
+  it('inlines Platform.select in the code when using an ObjectMethod', () => {
+    const code = `
+      function a() {
+        var a = Platform.select({
+          ios() { return 1; },
+          async* android(a, b) { return 2; },
+        });
+      }
+    `;
+    const expected = `
+      function a() {
+        var a = async function*(a, b) { return 2; };
+      }
+    `;
+    compare([inlinePlugin], code, expected, {
+      inlinePlatform: 'true',
+      platform: 'android',
+    });
+  });
+
+  it('inlines Platform.select in the code when using an ObjectMethod with string keys', () => {
+    const code = `
+      function a() {
+        var a = Platform.select({
+          "ios"() { return 1; },
+          "android"() { return 2; },
+        });
+      }
+    `;
+    const expected = `
+      function a() {
+        var a = function() { return 2; };
+      }
+    `;
+    compare([inlinePlugin], code, expected, {
+      inlinePlatform: 'true',
+      platform: 'android',
+    });
+  });
+
   it('does not inline Platform.select in the code when some of the properties are dynamic', () => {
     const code = `
       function a() {
@@ -340,6 +380,53 @@ describe('inline constants', () => {
     });
   });
 
+  it('does not inline Platform.select when ObjectMethod properties are dynamic', () => {
+    const code = `
+      function a() {
+        const COMPUTED_IOS = 'ios';
+        const COMPUTED_ANDROID = 'android';
+        var a = Platform.select({[COMPUTED_ANDROID]() {}, [COMPUTED_IOS]() {}});
+      }
+    `;
+
+    compare([inlinePlugin], code, code, {
+      inlinePlatform: true,
+      platform: 'android',
+    });
+  });
+
+  it('does not inline Platform.select when the object has a getter or setter', () => {
+    const code = `
+      function a() {
+        var a = Platform.select({
+          get ios() {},
+          get android() {},
+        });
+      }
+    `;
+
+    compare([inlinePlugin], code, code, {
+      inlinePlatform: true,
+      platform: 'android',
+    });
+  });
+
+  it('does not inline Platform.select when the object has a spread', () => {
+    const code = `
+      function a() {
+        var a = Platform.select({
+          ...ios,
+          ...android,
+        });
+      }
+    `;
+
+    compare([inlinePlugin], code, code, {
+      inlinePlatform: true,
+      platform: 'android',
+    });
+  });
+
   it('does not inline Platform.select if it receives a non-object', () => {
     const code = `
       function a() {

packages/metro-transform-plugins/src/inline-plugin.js

@@ -56,11 +56,12 @@ function inlinePlugin(
   const {
     isAssignmentExpression,
     isIdentifier,
-    isStringLiteral,
     isMemberExpression,
+    isObjectExpression,
+    isObjectMethod,
     isObjectProperty,
     isSpreadElement,
-    isObjectExpression,
+    isStringLiteral,
   } = t;
   const {isPlatformNode, isPlatformSelectNode} = createInlinePlatformChecks(
     t,
@@ -99,16 +100,20 @@ function inlinePlugin(
     let value = null;
 
     for (const p of objectExpression.properties) {
-      if (!isObjectProperty(p)) {
+      if (!isObjectProperty(p) && !isObjectMethod(p)) {
         continue;
       }
-
       if (
         (isIdentifier(p.key) && p.key.name === key) ||
         (isStringLiteral(p.key) && p.key.value === key)
       ) {
-        value = p.value;
-        break;
+        if (isObjectProperty(p)) {
+          value = p.value;
+          break;
+        } else if (isObjectMethod(p)) {
+          value = t.toExpression(p);
+          break;
+        }
       }
     }
 
@@ -120,6 +125,9 @@ function inlinePlugin(
       if (p.computed || isSpreadElement(p)) {
         return false;
       }
+      if (isObjectMethod(p) && p.kind !== 'method') {
+        return false;
+      }
 
       return isIdentifier(p.key) || isStringLiteral(p.key);
     });