fix: drop moment-precise-range-plugin dependency (#141)

Fixes #140

This change just inlines the code into this package, since the way that the
plugin installed itself on the moment package was fragile.

package.json

@@ -37,7 +37,7 @@
   "homepage": "https://github.com/decaffeinate/bulk-decaffeinate#readme",
   "devDependencies": {
     "babel-cli": "^6.16.0",
-    "babel-eslint": "^7.0.0",
+    "babel-eslint": "^8.1.2",
     "babel-plugin-external-helpers": "^6.8.0",
     "babel-plugin-syntax-async-functions": "^6.13.0",
     "babel-plugin-transform-regenerator": "^6.11.4",
@@ -60,7 +60,6 @@
     "executable": "^4.1.0",
     "fs-promise": "^1.0.0",
     "moment": "^2.19.1",
-    "moment-precise-range-plugin": "^1.2.4",
     "mz": "^2.4.0",
     "opn": "^4.0.2",
     "require-uncached": "^1.0.2",

src/runner/runWithProgressBar.js

@@ -1,9 +1,9 @@
 import moment from 'moment';
-import 'moment-precise-range-plugin';
 
 import runInParallel from './runInParallel';
 import CLIError from '../util/CLIError';
 import pluralize from '../util/pluralize';
+import momentPreciseDiff from '../util/momentPreciseDiff';
 
 /**
  * Run the given command in parallel, showing a progress bar of results.
@@ -35,7 +35,9 @@ export default async function runWithProgressBar(
     });
   } finally {
     process.stdout.write('\n');
-    console.log(`Finished in ${startTime.preciseDiff() || '0 seconds'} (Time: ${moment().format()})`);
+    let endTime = moment();
+    let diffStr = momentPreciseDiff(startTime, endTime) || '0 seconds';
+    console.log(`Finished in ${diffStr} (Time: ${moment().format()})`);
   }
   return results;
 }

src/util/momentPreciseDiff.js

@@ -0,0 +1,107 @@
+/**
+ * Copied from moment-precise-range, which is MIT-licensed, with minor cleanups
+ * to appease ESLint and remove an unused option.
+ *
+ * https://github.com/codebox/moment-precise-range
+ *
+ * The original plugin worked by modifying the global moment installation, which
+ * caused problems if multiple moment instances were installed, so this should
+ * avoid that.
+ */
+
+import moment from 'moment';
+
+const STRINGS = {
+  nodiff: '',
+  year: 'year',
+  years: 'years',
+  month: 'month',
+  months: 'months',
+  day: 'day',
+  days: 'days',
+  hour: 'hour',
+  hours: 'hours',
+  minute: 'minute',
+  minutes: 'minutes',
+  second: 'second',
+  seconds: 'seconds',
+  delimiter: ' ',
+};
+
+function pluralize(num, word) {
+  return num + ' ' + STRINGS[word + (num === 1 ? '' : 's')];
+}
+
+function buildStringFromValues(yDiff, mDiff, dDiff, hourDiff, minDiff, secDiff){
+  let result = [];
+
+  if (yDiff) {
+    result.push(pluralize(yDiff, 'year'));
+  }
+  if (mDiff) {
+    result.push(pluralize(mDiff, 'month'));
+  }
+  if (dDiff) {
+    result.push(pluralize(dDiff, 'day'));
+  }
+  if (hourDiff) {
+    result.push(pluralize(hourDiff, 'hour'));
+  }
+  if (minDiff) {
+    result.push(pluralize(minDiff, 'minute'));
+  }
+  if (secDiff) {
+    result.push(pluralize(secDiff, 'second'));
+  }
+
+  return result.join(STRINGS.delimiter);
+}
+
+export default function momentPreciseDiff(m1, m2) {
+  m1.add(m2.utcOffset() - m1.utcOffset(), 'minutes'); // shift timezone of m1 to m2
+
+  if (m1.isSame(m2)) {
+    return STRINGS.nodiff;
+  }
+
+  if (m1.isAfter(m2)) {
+    let tmp = m1;
+    m1 = m2;
+    m2 = tmp;
+  }
+
+  let yDiff = m2.year() - m1.year();
+  let mDiff = m2.month() - m1.month();
+  let dDiff = m2.date() - m1.date();
+  let hourDiff = m2.hour() - m1.hour();
+  let minDiff = m2.minute() - m1.minute();
+  let secDiff = m2.second() - m1.second();
+
+  if (secDiff < 0) {
+    secDiff = 60 + secDiff;
+    minDiff--;
+  }
+  if (minDiff < 0) {
+    minDiff = 60 + minDiff;
+    hourDiff--;
+  }
+  if (hourDiff < 0) {
+    hourDiff = 24 + hourDiff;
+    dDiff--;
+  }
+  if (dDiff < 0) {
+    let daysInLastFullMonth = moment(m2.year() + '-' + (m2.month() + 1), 'YYYY-MM').subtract(1, 'M').daysInMonth();
+    if (daysInLastFullMonth < m1.date()) { // 31/01 -> 2/03
+      dDiff = daysInLastFullMonth + dDiff + (m1.date() - daysInLastFullMonth);
+    } else {
+      dDiff = daysInLastFullMonth + dDiff;
+    }
+    mDiff--;
+  }
+  if (mDiff < 0) {
+    mDiff = 12 + mDiff;
+    yDiff--;
+  }
+
+  return buildStringFromValues(yDiff, mDiff, dDiff, hourDiff, minDiff, secDiff);
+}