fix(cp-frontend): gracefully handle multiple postinstall executions

checks if the webpack backup exists already before trying to create it

packages/cp-frontend/package.json

@@ -41,6 +41,7 @@
     "unitcalc": "^1.0.4"
   },
   "devDependencies": {
+    "apr-main": "^1.0.7",
     "babel-plugin-inline-react-svg": "^0.4.0",
     "babel-plugin-styled-components": "^1.1.4",
     "babel-preset-joyent-portal": "^1.0.0",
@@ -52,6 +53,7 @@
     "jest-matcher-utils": "^20.0.3",
     "jest-snapshot": "^20.0.3",
     "jest-styled-components": "^2.0.0",
+    "mz": "^2.6.0",
     "npm-run-all": "^4.0.2",
     "react-scripts": "^1.0.0",
     "react-test-renderer": "^15.5.4",

packages/cp-frontend/scripts/postinstall.js

@@ -1,7 +1,11 @@
-const fs = require('fs');
+const { readFile, writeFile, exists } = require('mz/fs');
+const main = require('apr-main');
 const path = require('path');
 
 // TODO: this will need to happen for prod and test too
+
+const enhancedConfigPath = path.join(__dirname, './webpack.config.dev.js');
+
 const configPath = path.join(
   __dirname,
   '../node_modules/react-scripts/config/webpack.config.dev.js'
@@ -10,30 +14,15 @@ const orignalConfigPath = path.join(
   __dirname,
   '../node_modules/react-scripts/config/webpack.config.dev.original.js'
 );
-const enhancedConfigPath = path.join(__dirname, './webpack.config.dev.js');
 
-// bit of healthy callback hell for making it spicy
+main((async () => {
-fs.readFile(configPath, (error, orignalConfig) => {
+  const orignalConfigPathExists = await exists(orignalConfigPath);
-  if (error) {
-    console.log('Original config read error', error);
-  } else {
-    fs.writeFile(orignalConfigPath, orignalConfig, error => {
-      if (error) {
-        console.log('Original config write error', error);
-      } else {
-        fs.readFile(enhancedConfigPath, (error, enhancedConfig) => {
-          if (error) {
-            console.log('Enhanced config read error', error);
-          } else {
-            fs.writeFile(configPath, enhancedConfig, error => {
-              if (error) {
-                console.log('Enhanced config write error', error);
-              }
-            });
-          }
-        });
-      }
-    });
-  }
-});
 
+  if (!orignalConfigPathExists) {
+    const orignalConfig = await readFile(configPath, 'utf-8');
+    await writeFile(orignalConfigPath, orignalConfig);
+  }
+
+  const enhancedConfig = await readFile(enhancedConfigPath);
+  await writeFile(configPath, enhancedConfig)
+})());

packages/cp-frontend/yarn.lock

@@ -147,6 +147,10 @@ ansi-styles@^3.0.0:
   dependencies:
     color-convert "^1.0.0"
 
+any-promise@^1.0.0:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/any-promise/-/any-promise-1.3.0.tgz#abc6afeedcea52e809cdc0376aed3ce39635d17f"
+
 anymatch@^1.3.0:
   version "1.3.0"
   resolved "https://registry.yarnpkg.com/anymatch/-/anymatch-1.3.0.tgz#a3e52fa39168c825ff57b0248126ce5a8ff95507"
@@ -190,6 +194,12 @@ append-transform@^0.4.0:
   dependencies:
     default-require-extensions "^1.0.0"
 
+apr-main@^1.0.7:
+  version "1.0.7"
+  resolved "https://registry.yarnpkg.com/apr-main/-/apr-main-1.0.7.tgz#4f2592e20cb236b09c3c3d98a95088fbcc5fad4d"
+  dependencies:
+    lodash.isfunction "^3.0.8"
+
 aproba@^1.0.3:
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/aproba/-/aproba-1.1.1.tgz#95d3600f07710aa0e9298c726ad5ecf2eacbabab"
@@ -4114,6 +4124,10 @@ lodash.isequal@^4.1.1:
   version "4.5.0"
   resolved "https://registry.yarnpkg.com/lodash.isequal/-/lodash.isequal-4.5.0.tgz#415c4478f2bcc30120c22ce10ed3226f7d3e18e0"
 
+lodash.isfunction@^3.0.8:
+  version "3.0.8"
+  resolved "https://registry.yarnpkg.com/lodash.isfunction/-/lodash.isfunction-3.0.8.tgz#4db709fc81bc4a8fd7127a458a5346c5cdce2c6b"
+
 lodash.isobject@^3.0.2:
   version "3.0.2"
   resolved "https://registry.yarnpkg.com/lodash.isobject/-/lodash.isobject-3.0.2.tgz#3c8fb8d5b5bf4bf90ae06e14f2a530a4ed935e1d"
@@ -4359,6 +4373,14 @@ mute-stream@0.0.7:
   version "0.0.7"
   resolved "https://registry.yarnpkg.com/mute-stream/-/mute-stream-0.0.7.tgz#3075ce93bc21b8fab43e1bc4da7e8115ed1e7bab"
 
+mz@^2.6.0:
+  version "2.6.0"
+  resolved "https://registry.yarnpkg.com/mz/-/mz-2.6.0.tgz#c8b8521d958df0a4f2768025db69c719ee4ef1ce"
+  dependencies:
+    any-promise "^1.0.0"
+    object-assign "^4.0.1"
+    thenify-all "^1.0.0"
+
 nan@^2.3.0:
   version "2.6.2"
   resolved "https://registry.yarnpkg.com/nan/-/nan-2.6.2.tgz#e4ff34e6c95fdfb5aecc08de6596f43605a7db45"
@@ -6575,6 +6597,18 @@ text-table@0.2.0, text-table@^0.2.0, text-table@~0.2.0:
   version "0.2.0"
   resolved "https://registry.yarnpkg.com/text-table/-/text-table-0.2.0.tgz#7f5ee823ae805207c00af2df4a84ec3fcfa570b4"
 
+thenify-all@^1.0.0:
+  version "1.6.0"
+  resolved "https://registry.yarnpkg.com/thenify-all/-/thenify-all-1.6.0.tgz#1a1918d402d8fc3f98fbf234db0bcc8cc10e9726"
+  dependencies:
+    thenify ">= 3.1.0 < 4"
+
+"thenify@>= 3.1.0 < 4":
+  version "3.3.0"
+  resolved "https://registry.yarnpkg.com/thenify/-/thenify-3.3.0.tgz#e69e38a1babe969b0108207978b9f62b88604839"
+  dependencies:
+    any-promise "^1.0.0"
+
 throat@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/throat/-/throat-3.0.0.tgz#e7c64c867cbb3845f10877642f7b60055b8ec0d6"