Add optional chaining and nullish coalescing operators support

package.json

@@ -35,6 +35,8 @@
     "@babel/core": "^7.4.4",
     "@babel/helper-module-imports": "^7.0.0",
     "@babel/plugin-proposal-class-properties": "^7.4.4",
+    "@babel/plugin-proposal-nullish-coalescing-operator": "^7.7.4",
+    "@babel/plugin-proposal-optional-chaining": "^7.7.5",
     "@babel/plugin-syntax-dynamic-import": "^7.2.0",
     "@babel/plugin-transform-regenerator": "^7.4.5",
     "@babel/plugin-transform-runtime": "^7.6.0",
@@ -78,7 +80,7 @@
     "mkdirp": "^0.5.1",
     "ora": "^3.4.0",
     "pascal-case": "^2.0.1",
-    "prettier": "^1.18.2",
+    "prettier": "^1.19.1",
     "progress-estimator": "^0.2.2",
     "rimraf": "^3.0.0",
     "rollup": "^1.27.8",

src/babelPluginTsdx.ts

@@ -86,6 +86,10 @@ export const babelPluginTsdx = babelPlugin.custom((babelCore: any) => ({
           name: '@babel/plugin-proposal-class-properties',
           loose: true,
         },
+        // Adds syntax support for optional chaining (.?)
+        { name: '@babel/plugin-proposal-optional-chaining' },
+        // Adds syntax support for default value using ?? operator
+        { name: '@babel/plugin-proposal-nullish-coalescing-operator' },
         {
           name: '@babel/plugin-transform-regenerator',
           async: false,

test/fixtures/build-default/src/index.ts

@@ -1,3 +1,6 @@
+import './syntax/nullish-coalescing';
+import './syntax/optional-chaining';
+
 export { foo } from './foo';
 
 export const sum = (a: number, b: number) => {

test/fixtures/build-default/src/syntax/nullish-coalescing.ts

@@ -0,0 +1,5 @@
+// https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html#nullish-coalescing
+
+const bar = () => {};
+const foo = false;
+export const x = foo ?? bar();

test/fixtures/build-default/src/syntax/optional-chaining.ts

@@ -0,0 +1,3 @@
+// https://www.typescriptlang.org/docs/handbook/release-notes/typescript-3-7.html#optional-chaining
+
+export const foo = (foo?: { bar: string }) => foo?.bar || 'bar';

yarn.lock

@@ -262,6 +262,14 @@
     "@babel/helper-plugin-utils" "^7.0.0"
     "@babel/plugin-syntax-json-strings" "^7.2.0"
 
+"@babel/plugin-proposal-nullish-coalescing-operator@^7.7.4":
+  version "7.7.4"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-nullish-coalescing-operator/-/plugin-proposal-nullish-coalescing-operator-7.7.4.tgz#7db302c83bc30caa89e38fee935635ef6bd11c28"
+  integrity sha512-TbYHmr1Gl1UC7Vo2HVuj/Naci5BEGNZ0AJhzqD2Vpr6QPFWpUmBRLrIDjedzx7/CShq0bRDS2gI4FIs77VHLVQ==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+    "@babel/plugin-syntax-nullish-coalescing-operator" "^7.7.4"
+
 "@babel/plugin-proposal-object-rest-spread@^7.6.2":
   version "7.6.2"
   resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-object-rest-spread/-/plugin-proposal-object-rest-spread-7.6.2.tgz#8ffccc8f3a6545e9f78988b6bf4fe881b88e8096"
@@ -278,6 +286,14 @@
     "@babel/helper-plugin-utils" "^7.0.0"
     "@babel/plugin-syntax-optional-catch-binding" "^7.2.0"
 
+"@babel/plugin-proposal-optional-chaining@^7.7.5":
+  version "7.7.5"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-optional-chaining/-/plugin-proposal-optional-chaining-7.7.5.tgz#f0835f044cef85b31071a924010a2a390add11d4"
+  integrity sha512-sOwFqT8JSchtJeDD+CjmWCaiFoLxY4Ps7NjvwHC/U7l4e9i5pTRNt8nDMIFSOUL+ncFbYSwruHM8WknYItWdXw==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+    "@babel/plugin-syntax-optional-chaining" "^7.7.4"
+
 "@babel/plugin-proposal-unicode-property-regex@^7.6.2":
   version "7.6.2"
   resolved "https://registry.yarnpkg.com/@babel/plugin-proposal-unicode-property-regex/-/plugin-proposal-unicode-property-regex-7.6.2.tgz#05413762894f41bfe42b9a5e80919bd575dcc802"
@@ -308,6 +324,13 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.0.0"
 
+"@babel/plugin-syntax-nullish-coalescing-operator@^7.7.4":
+  version "7.7.4"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-nullish-coalescing-operator/-/plugin-syntax-nullish-coalescing-operator-7.7.4.tgz#e53b751d0c3061b1ba3089242524b65a7a9da12b"
+  integrity sha512-XKh/yIRPiQTOeBg0QJjEus5qiSKucKAiApNtO1psqG7D17xmE+X2i5ZqBEuSvo0HRuyPaKaSN/Gy+Ha9KFQolw==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+
 "@babel/plugin-syntax-object-rest-spread@^7.0.0", "@babel/plugin-syntax-object-rest-spread@^7.2.0":
   version "7.2.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-object-rest-spread/-/plugin-syntax-object-rest-spread-7.2.0.tgz#3b7a3e733510c57e820b9142a6579ac8b0dfad2e"
@@ -322,6 +345,13 @@
   dependencies:
     "@babel/helper-plugin-utils" "^7.0.0"
 
+"@babel/plugin-syntax-optional-chaining@^7.7.4":
+  version "7.7.4"
+  resolved "https://registry.yarnpkg.com/@babel/plugin-syntax-optional-chaining/-/plugin-syntax-optional-chaining-7.7.4.tgz#c91fdde6de85d2eb8906daea7b21944c3610c901"
+  integrity sha512-2MqYD5WjZSbJdUagnJvIdSfkb/ucOC9/1fRJxm7GAxY6YQLWlUvkfxoNbUPcPLHJyetKUDQ4+yyuUyAoc0HriA==
+  dependencies:
+    "@babel/helper-plugin-utils" "^7.0.0"
+
 "@babel/plugin-transform-arrow-functions@^7.2.0":
   version "7.2.0"
   resolved "https://registry.yarnpkg.com/@babel/plugin-transform-arrow-functions/-/plugin-transform-arrow-functions-7.2.0.tgz#9aeafbe4d6ffc6563bf8f8372091628f00779550"
@@ -4732,10 +4762,10 @@ prettier-linter-helpers@^1.0.0:
   dependencies:
     fast-diff "^1.1.2"
 
-prettier@^1.18.2:
-  version "1.18.2"
-  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.18.2.tgz#6823e7c5900017b4bd3acf46fe9ac4b4d7bda9ea"
-  integrity sha512-OeHeMc0JhFE9idD4ZdtNibzY0+TPHSpSSb9h8FqtP+YnoZZ1sl8Vc9b1sasjfymH3SonAF4QcA2+mzHPhMvIiw==
+prettier@^1.19.1:
+  version "1.19.1"
+  resolved "https://registry.yarnpkg.com/prettier/-/prettier-1.19.1.tgz#f7d7f5ff8a9cd872a7be4ca142095956a60797cb"
+  integrity sha512-s7PoyDv/II1ObgQunCbB9PdLmUcBZcnWOcxDh7O0N/UwDEsHyqkW+Qh28jW+mVuCdx7gLB0BotYI1Y6uI9iyew==
 
 pretty-format@^24.9.0:
   version "24.9.0"