Annotate pure calls to enable treeshaking (jaredpalmer#976)

In this diff I tweaked esm output with PURE annotations like this

```
var _a;
var FormikProvider = (_a =
/*#__PURE__*/
createContext({}), _a.Provider),
    FormikConsumer = _a.Consumer;
function connect(Comp) {
  var C = function (props) {
    return createElement(FormikConsumer, null, function (formik) {
      return createElement(Comp, __assign({}, props, {
        formik: formik
      }));
    });
  };

  C.WrappedComponent = Comp;
  return hoistNonReactStatics(C, Comp);
}

```

They will allow webpack and uglify to eliminate more unused code. Take a
look at size snapshot.

.size-snapshot.json

@@ -15,21 +15,21 @@
     "gzipped": 5533
   },
   "dist/index.js": {
-    "bundled": 41589,
+    "bundled": 38223,
     "minified": 21696,
     "gzipped": 5577
   },
   "dist/formik.esm.js": {
-    "bundled": 40381,
+    "bundled": 37015,
     "minified": 20594,
     "gzipped": 5405,
     "treeshaked": {
       "rollup": {
-        "code": 16176,
+        "code": 628,
         "import_statements": 345
       },
       "webpack": {
-        "code": 18196
+        "code": 3269
       }
     }
   }

package.json

@@ -57,6 +57,7 @@
     "@types/react-dom": "16.0.7"
   },
   "devDependencies": {
+    "@babel/core": "^7.1.2",
     "@pisano/enzyme": "^3.3.0-pisano.public.1",
     "@pisano/enzyme-adapter-react-16": "^1.1.1-pisano.public.1",
     "@storybook/addon-options": "^3.4.8",
@@ -71,6 +72,7 @@
     "@types/yup": "^0.24.9",
     "all-contributors-cli": "^4.4.0",
     "awesome-typescript-loader": "^3.4.1",
+    "babel-plugin-annotate-pure-calls": "^0.4.0",
     "cross-env": "5.0.5",
     "doctoc": "^1.3.0",
     "enzyme": "^3.6.0",
@@ -85,6 +87,7 @@
     "react-dom": "^16.5.0",
     "rimraf": "^2.6.2",
     "rollup": "^0.66.4",
+    "rollup-plugin-babel": "^4.0.3",
     "rollup-plugin-commonjs": "^9.1.8",
     "rollup-plugin-node-resolve": "^3.4.0",
     "rollup-plugin-replace": "^2.1.0",

rollup.config.js

@@ -2,6 +2,7 @@ import commonjs from 'rollup-plugin-commonjs';
 import replace from 'rollup-plugin-replace';
 import resolve from 'rollup-plugin-node-resolve';
 import sourceMaps from 'rollup-plugin-sourcemaps';
+import babel from 'rollup-plugin-babel';
 import { uglify } from 'rollup-plugin-uglify';
 import { sizeSnapshot } from 'rollup-plugin-size-snapshot';
 import pkg from './package.json';
@@ -101,6 +102,13 @@ export default [
         sourcemap: true,
       },
     ],
-    plugins: [resolve(), sizeSnapshot(), sourceMaps()],
+    plugins: [
+      resolve(),
+      babel({
+        plugins: ['babel-plugin-annotate-pure-calls'],
+      }),
+      sizeSnapshot(),
+      sourceMaps(),
+    ],
   },
 ];

yarn.lock

@@ -16,6 +16,76 @@
   dependencies:
     "@babel/highlight" "7.0.0-beta.46"
 
+"@babel/core@^7.1.2":
+  version "7.1.2"
+  resolved "https://registry.yarnpkg.com/@babel/core/-/core-7.1.2.tgz#f8d2a9ceb6832887329a7b60f9d035791400ba4e"
+  integrity sha512-IFeSSnjXdhDaoysIlev//UzHZbdEmm7D0EIH2qtse9xK7mXEZQpYjs2P00XlP1qYsYvid79p+Zgg6tz1mp6iVw==
+  dependencies:
+    "@babel/code-frame" "^7.0.0"
+    "@babel/generator" "^7.1.2"
+    "@babel/helpers" "^7.1.2"
+    "@babel/parser" "^7.1.2"
+    "@babel/template" "^7.1.2"
+    "@babel/traverse" "^7.1.0"
+    "@babel/types" "^7.1.2"
+    convert-source-map "^1.1.0"
+    debug "^3.1.0"
+    json5 "^0.5.0"
+    lodash "^4.17.10"
+    resolve "^1.3.2"
+    semver "^5.4.1"
+    source-map "^0.5.0"
+
+"@babel/generator@^7.0.0", "@babel/generator@^7.1.2":
+  version "7.1.2"
+  resolved "https://registry.yarnpkg.com/@babel/generator/-/generator-7.1.2.tgz#fde75c072575ce7abbd97322e8fef5bae67e4630"
+  integrity sha512-70A9HWLS/1RHk3Ck8tNHKxOoKQuSKocYgwDN85Pyl/RBduss6AKxUR7RIZ/lzduQMSYfWEM4DDBu6A+XGbkFig==
+  dependencies:
+    "@babel/types" "^7.1.2"
+    jsesc "^2.5.1"
+    lodash "^4.17.10"
+    source-map "^0.5.0"
+    trim-right "^1.0.1"
+
+"@babel/helper-function-name@^7.1.0":
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/@babel/helper-function-name/-/helper-function-name-7.1.0.tgz#a0ceb01685f73355d4360c1247f582bfafc8ff53"
+  integrity sha512-A95XEoCpb3TO+KZzJ4S/5uW5fNe26DjBGqf1o9ucyLyCmi1dXq/B3c8iaWTfBk3VvetUxl16e8tIrd5teOCfGw==
+  dependencies:
+    "@babel/helper-get-function-arity" "^7.0.0"
+    "@babel/template" "^7.1.0"
+    "@babel/types" "^7.0.0"
+
+"@babel/helper-get-function-arity@^7.0.0":
+  version "7.0.0"
+  resolved "https://registry.yarnpkg.com/@babel/helper-get-function-arity/-/helper-get-function-arity-7.0.0.tgz#83572d4320e2a4657263734113c42868b64e49c3"
+  integrity sha512-r2DbJeg4svYvt3HOS74U4eWKsUAMRH01Z1ds1zx8KNTPtpTL5JAsdFv8BNyOpVqdFhHkkRDIg5B4AsxmkjAlmQ==
+  dependencies:
+    "@babel/types" "^7.0.0"
+
+"@babel/helper-module-imports@^7.0.0":
+  version "7.0.0"
+  resolved "https://registry.yarnpkg.com/@babel/helper-module-imports/-/helper-module-imports-7.0.0.tgz#96081b7111e486da4d2cd971ad1a4fe216cc2e3d"
+  integrity sha512-aP/hlLq01DWNEiDg4Jn23i+CXxW/owM4WpDLFUbpjxe4NS3BhLVZQ5i7E0ZrxuQ/vwekIeciyamgB1UIYxxM6A==
+  dependencies:
+    "@babel/types" "^7.0.0"
+
+"@babel/helper-split-export-declaration@^7.0.0":
+  version "7.0.0"
+  resolved "https://registry.yarnpkg.com/@babel/helper-split-export-declaration/-/helper-split-export-declaration-7.0.0.tgz#3aae285c0311c2ab095d997b8c9a94cad547d813"
+  integrity sha512-MXkOJqva62dfC0w85mEf/LucPPS/1+04nmmRMPEBUB++hiiThQ2zPtX/mEWQ3mtzCEjIJvPY8nuwxXtQeQwUag==
+  dependencies:
+    "@babel/types" "^7.0.0"
+
+"@babel/helpers@^7.1.2":
+  version "7.1.2"
+  resolved "https://registry.yarnpkg.com/@babel/helpers/-/helpers-7.1.2.tgz#ab752e8c35ef7d39987df4e8586c63b8846234b5"
+  integrity sha512-Myc3pUE8eswD73aWcartxB16K6CGmHDv9KxOmD2CeOs/FaEAQodr3VYGmlvOmog60vNQ2w8QbatuahepZwrHiA==
+  dependencies:
+    "@babel/template" "^7.1.2"
+    "@babel/traverse" "^7.1.0"
+    "@babel/types" "^7.1.2"
+
 "@babel/[email protected]":
   version "7.0.0-beta.46"
   resolved "https://registry.yarnpkg.com/@babel/highlight/-/highlight-7.0.0-beta.46.tgz#c553c51e65f572bdedd6eff66fc0bb563016645e"
@@ -34,6 +104,44 @@
     esutils "^2.0.2"
     js-tokens "^4.0.0"
 
+"@babel/parser@^7.1.0", "@babel/parser@^7.1.2":
+  version "7.1.2"
+  resolved "https://registry.yarnpkg.com/@babel/parser/-/parser-7.1.2.tgz#85c5c47af6d244fab77bce6b9bd830e38c978409"
+  integrity sha512-x5HFsW+E/nQalGMw7hu+fvPqnBeBaIr0lWJ2SG0PPL2j+Pm9lYvCrsZJGIgauPIENx0v10INIyFjmSNUD/gSqQ==
+
+"@babel/template@^7.1.0", "@babel/template@^7.1.2":
+  version "7.1.2"
+  resolved "https://registry.yarnpkg.com/@babel/template/-/template-7.1.2.tgz#090484a574fef5a2d2d7726a674eceda5c5b5644"
+  integrity sha512-SY1MmplssORfFiLDcOETrW7fCLl+PavlwMh92rrGcikQaRq4iWPVH0MpwPpY3etVMx6RnDjXtr6VZYr/IbP/Ag==
+  dependencies:
+    "@babel/code-frame" "^7.0.0"
+    "@babel/parser" "^7.1.2"
+    "@babel/types" "^7.1.2"
+
+"@babel/traverse@^7.1.0":
+  version "7.1.0"
+  resolved "https://registry.yarnpkg.com/@babel/traverse/-/traverse-7.1.0.tgz#503ec6669387efd182c3888c4eec07bcc45d91b2"
+  integrity sha512-bwgln0FsMoxm3pLOgrrnGaXk18sSM9JNf1/nHC/FksmNGFbYnPWY4GYCfLxyP1KRmfsxqkRpfoa6xr6VuuSxdw==
+  dependencies:
+    "@babel/code-frame" "^7.0.0"
+    "@babel/generator" "^7.0.0"
+    "@babel/helper-function-name" "^7.1.0"
+    "@babel/helper-split-export-declaration" "^7.0.0"
+    "@babel/parser" "^7.1.0"
+    "@babel/types" "^7.0.0"
+    debug "^3.1.0"
+    globals "^11.1.0"
+    lodash "^4.17.10"
+
+"@babel/types@^7.0.0", "@babel/types@^7.1.2":
+  version "7.1.2"
+  resolved "https://registry.yarnpkg.com/@babel/types/-/types-7.1.2.tgz#183e7952cf6691628afdc2e2b90d03240bac80c0"
+  integrity sha512-pb1I05sZEKiSlMUV9UReaqsCPUpgbHHHu2n1piRm7JkuBkm6QxcaIzKu6FMnMtCbih/cEYTR+RGYYC96Yk9HAg==
+  dependencies:
+    esutils "^2.0.2"
+    lodash "^4.17.10"
+    to-fast-properties "^2.0.0"
+
 "@mrmlnc/readdir-enhanced@^2.2.1":
   version "2.2.1"
   resolved "https://registry.yarnpkg.com/@mrmlnc/readdir-enhanced/-/readdir-enhanced-2.2.1.tgz#524af240d1a360527b730475ecfa1344aa540dde"
@@ -1446,6 +1554,11 @@ babel-messages@^6.23.0:
   dependencies:
     babel-runtime "^6.22.0"
 
+babel-plugin-annotate-pure-calls@^0.4.0:
+  version "0.4.0"
+  resolved "https://registry.yarnpkg.com/babel-plugin-annotate-pure-calls/-/babel-plugin-annotate-pure-calls-0.4.0.tgz#78aa00fd878c4fcde4d49f3da397fcf5defbcce8"
+  integrity sha512-oi4M/PWUJOU9ZyRGoPTfPMqdyMp06jbJAomd3RcyYuzUtBOddv98BqLm96Lucpi2QFoQHkdGQt0ACvw7VzVEQA==
+
 babel-plugin-check-es2015-constants@^6.22.0:
   version "6.22.0"
   resolved "https://registry.yarnpkg.com/babel-plugin-check-es2015-constants/-/babel-plugin-check-es2015-constants-6.22.0.tgz#35157b101426fd2ffd3da3f75c7d1e91835bbf8a"
@@ -3096,6 +3209,13 @@ content-type@~1.0.4:
   resolved "https://registry.yarnpkg.com/content-type/-/content-type-1.0.4.tgz#e138cc75e040c727b1966fe5e5f8c9aee256fe3b"
   integrity sha512-hIP3EEPs8tB9AT1L+NUqtwOAps4mk2Zob89MWXMHjHWg9milF/j4osnnQLXBCBFBk/tvIG/tUc9mOUJiPBhPXA==
 
+convert-source-map@^1.1.0:
+  version "1.6.0"
+  resolved "https://registry.yarnpkg.com/convert-source-map/-/convert-source-map-1.6.0.tgz#51b537a8c43e0f04dec1993bffcdd504e758ac20"
+  integrity sha512-eFu7XigvxdZ1ETfbgPBohgyQ/Z++C0eEhTor0qRwBw9unw+L0/6V8wkSuGgzdThkiS5lSpdptOQPD8Ak40a+7A==
+  dependencies:
+    safe-buffer "~5.1.1"
+
 convert-source-map@^1.4.0, convert-source-map@^1.5.0, convert-source-map@^1.5.1:
   version "1.5.1"
   resolved "https://registry.yarnpkg.com/convert-source-map/-/convert-source-map-1.5.1.tgz#b8278097b9bc229365de5c62cf5fcaed8b5599e5"
@@ -4148,7 +4268,7 @@ estree-walker@^0.3.0:
   resolved "https://registry.yarnpkg.com/estree-walker/-/estree-walker-0.3.1.tgz#e6b1a51cf7292524e7237c312e5fe6660c1ce1aa"
   integrity sha1-5rGlHPcpJSTnI3wxLl/mZgwc4ao=
 
-estree-walker@^0.5.1:
+estree-walker@^0.5.1, estree-walker@^0.5.2:
   version "0.5.2"
   resolved "https://registry.yarnpkg.com/estree-walker/-/estree-walker-0.5.2.tgz#d3850be7529c9580d815600b53126515e146dd39"
   integrity sha512-XpCnW/AE10ws/kDAs37cngSkvgIR8aN3G0MS85m7dUpuK2EREo9VJ00uvw6Dg/hXEpfsE1I1TvJOJr+Z+TL+ig==
@@ -4897,6 +5017,11 @@ global@^4.3.2:
     min-document "^2.19.0"
     process "~0.5.1"
 
+globals@^11.1.0:
+  version "11.8.0"
+  resolved "https://registry.yarnpkg.com/globals/-/globals-11.8.0.tgz#c1ef45ee9bed6badf0663c5cb90e8d1adec1321d"
+  integrity sha512-io6LkyPVuzCHBSQV9fmOwxZkUk6nIaGmxheLDgmuFv89j0fm2aqDbIXKAGfzCMHqz3HLF2Zf8WSG6VqMh2qFmA==
+
 globals@^9.18.0:
   version "9.18.0"
   resolved "https://registry.yarnpkg.com/globals/-/globals-9.18.0.tgz#aa3896b3e69b487f17e31ed2143d69a8e30c2d8a"
@@ -6490,6 +6615,11 @@ jsesc@^1.3.0:
   resolved "https://registry.yarnpkg.com/jsesc/-/jsesc-1.3.0.tgz#46c3fec8c1892b12b0833db9bc7622176dbab34b"
   integrity sha1-RsP+yMGJKxKwgz25vHYiF226s0s=
 
+jsesc@^2.5.1:
+  version "2.5.1"
+  resolved "https://registry.yarnpkg.com/jsesc/-/jsesc-2.5.1.tgz#e421a2a8e20d6b0819df28908f782526b96dd1fe"
+  integrity sha1-5CGiqOINawgZ3yiQj3glJrlt0f4=
+
 jsesc@~0.5.0:
   version "0.5.0"
   resolved "https://registry.yarnpkg.com/jsesc/-/jsesc-0.5.0.tgz#e7dee66e35d6fc16f710fe91d5cf69f70f08911d"
@@ -9372,6 +9502,14 @@ ripemd160@^2.0.0, ripemd160@^2.0.1:
     hash-base "^3.0.0"
     inherits "^2.0.1"
 
+rollup-plugin-babel@^4.0.3:
+  version "4.0.3"
+  resolved "https://registry.yarnpkg.com/rollup-plugin-babel/-/rollup-plugin-babel-4.0.3.tgz#8282b0e22233160d679e9c7631342e848422fb02"
+  integrity sha512-/PP0MgbPQyRywI4zRIJim6ySjTcOLo4kQbEbROqp9kOR3kHC3FeU++QpBDZhS2BcHtJTVZMVbBV46flbBN5zxQ==
+  dependencies:
+    "@babel/helper-module-imports" "^7.0.0"
+    rollup-pluginutils "^2.3.0"
+
 rollup-plugin-commonjs@^9.1.8:
   version "9.1.8"
   resolved "https://registry.yarnpkg.com/rollup-plugin-commonjs/-/rollup-plugin-commonjs-9.1.8.tgz#4113ed94e6054b5f8a3501d8811f934cadde3246"
@@ -9450,6 +9588,14 @@ rollup-pluginutils@^2.0.1:
     estree-walker "^0.3.0"
     micromatch "^2.3.11"
 
+rollup-pluginutils@^2.3.0:
+  version "2.3.3"
+  resolved "https://registry.yarnpkg.com/rollup-pluginutils/-/rollup-pluginutils-2.3.3.tgz#3aad9b1eb3e7fe8262820818840bf091e5ae6794"
+  integrity sha512-2XZwja7b6P5q4RZ5FhyX1+f46xi1Z3qBKigLRZ6VTZjwbN0K1IFGMlwm06Uu0Emcre2Z63l77nq/pzn+KxIEoA==
+  dependencies:
+    estree-walker "^0.5.2"
+    micromatch "^2.3.11"
+
 rollup@^0.66.4:
   version "0.66.4"
   resolved "https://registry.yarnpkg.com/rollup/-/rollup-0.66.4.tgz#8067b9638af82873b7fd644af9c3d72108ca4bab"
@@ -9868,7 +10014,7 @@ source-map-url@^0.4.0:
   resolved "https://registry.yarnpkg.com/source-map-url/-/source-map-url-0.4.0.tgz#3e935d7ddd73631b97659956d55128e87b5084a3"
   integrity sha1-PpNdfd1zYxuXZZlW1VEo6HtQhKM=
 
-[email protected], source-map@^0.5.3, source-map@^0.5.6, source-map@^0.5.7, source-map@~0.5.0, source-map@~0.5.1:
+[email protected], source-map@^0.5.0, source-map@^0.5.3, source-map@^0.5.6, source-map@^0.5.7, source-map@~0.5.0, source-map@~0.5.1:
   version "0.5.7"
   resolved "https://registry.yarnpkg.com/source-map/-/source-map-0.5.7.tgz#8a039d2d1021d22d1ea14c80d8ea468ba2ef3fcc"
   integrity sha1-igOdLRAh0i0eoUyA2OpGi6LvP8w=
@@ -10401,6 +10547,11 @@ to-fast-properties@^1.0.3:
   resolved "https://registry.yarnpkg.com/to-fast-properties/-/to-fast-properties-1.0.3.tgz#b83571fa4d8c25b82e231b06e3a3055de4ca1a47"
   integrity sha1-uDVx+k2MJbguIxsG46MFXeTKGkc=
 
+to-fast-properties@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/to-fast-properties/-/to-fast-properties-2.0.0.tgz#dc5e698cbd079265bc73e0377681a4e4e83f616e"
+  integrity sha1-3F5pjL0HkmW8c+A3doGk5Og/YW4=
+
 to-object-path@^0.3.0:
   version "0.3.0"
   resolved "https://registry.yarnpkg.com/to-object-path/-/to-object-path-0.3.0.tgz#297588b7b0e7e0ac08e04e672f85c1f4999e17af"