[New Exercise] Ledger (#2398)

* Adding autogenerated files

* Adding scaffolding, tests and solution

* Accidentally deleted a key in `config.json`

* Update proof.ci.js

config.json

@@ -2598,6 +2598,16 @@
           "strings"
         ],
         "difficulty": 2
+      },
+      {
+        "slug": "ledger",
+        "name": "Ledger",
+        "uuid": "8716b347-e18f-48a6-b373-426cc4ca98cb",
+        "practices": [],
+        "prerequisites": [
+          "string-formatting"
+        ],
+        "difficulty": 5
       }
     ]
   },

exercises/practice/ledger/.docs/instructions.md

@@ -0,0 +1,14 @@
+# Instructions
+
+Refactor a ledger printer.
+
+The ledger exercise is a refactoring exercise.
+There is code that prints a nicely formatted ledger, given a locale (American or Dutch) and a currency (US dollar or euro).
+The code however is rather badly written, though (somewhat surprisingly) it consistently passes the test suite.
+
+Rewrite this code.
+Remember that in refactoring the trick is to make small steps that keep the tests passing.
+That way you can always quickly go back to a working version.
+Version control tools like git can help here as well.
+
+Please keep a log of what changes you've made and make a comment on the exercise containing that log, this will help reviewers.

exercises/practice/ledger/.eslintrc

@@ -0,0 +1,14 @@
+{
+  "root": true,
+  "extends": "@exercism/eslint-config-javascript",
+  "env": {
+    "jest": true
+  },
+  "overrides": [
+    {
+      "files": [".meta/proof.ci.js", ".meta/exemplar.js", "*.spec.js"],
+      "excludedFiles": ["custom.spec.js"],
+      "extends": "@exercism/eslint-config-javascript/maintainers"
+    }
+  ]
+}

exercises/practice/ledger/.gitignore

@@ -0,0 +1,5 @@
+/node_modules
+/bin/configlet
+/bin/configlet.exe
+/pnpm-lock.yaml
+/yarn.lock

exercises/practice/ledger/.meta/config.json

@@ -0,0 +1,17 @@
+{
+  "authors": [
+    "Cool-Katt"
+  ],
+  "files": {
+    "solution": [
+      "ledger.js"
+    ],
+    "test": [
+      "ledger.spec.js"
+    ],
+    "example": [
+      ".meta/proof.ci.js"
+    ]
+  },
+  "blurb": "Refactor a ledger printer."
+}

exercises/practice/ledger/.meta/proof.ci.js

@@ -0,0 +1,99 @@
+class LedgerEntry {
+  constructor(date, description, change) {
+    this.date = new Date(date);
+    this.description = description;
+    this.change = change;
+  }
+}
+
+class FormattedLedgerEntry {
+  constructor(entry, locale, dateFormat, currencyFormat) {
+    this.entry = entry;
+    this.locale = locale;
+    this.dateFormat = dateFormat;
+    this.currencyFormat = currencyFormat;
+  }
+
+  date() {
+    return this.entry.date.toLocaleDateString(this.locale, this.dateFormat);
+  }
+
+  description(length = 25) {
+    if (this.entry.description.length > length) {
+      return `${this.entry.description.substring(0, length - 3)}...`;
+    }
+
+    return this.entry.description.padEnd(length, ' ');
+  }
+
+  change(offset = 13) {
+    const formatted = (this.entry.change / 100).toLocaleString(
+      this.locale,
+      this.currencyFormat,
+    );
+
+    const trailingSpace = formatted.includes(')') ? '' : ' ';
+    return `${formatted}${trailingSpace}`.padStart(offset, ' ');
+  }
+
+  toTableRow() {
+    return [this.date(), this.description(), this.change()].join(' | ');
+  }
+}
+
+const OPTIONS = {
+  HEADERS: {
+    'en-US': ['Date', 'Description', 'Change'],
+    'nl-NL': ['Datum', 'Omschrijving', 'Verandering'],
+  },
+  headerRow: function (locale) {
+    const [date, description, change] = this.HEADERS[locale];
+    return [
+      date.padEnd(10, ' '),
+      description.padEnd(25, ' '),
+      change.padEnd(13, ' '),
+    ].join(' | ');
+  },
+  dateFormatOptions: function () {
+    return {
+      day: '2-digit',
+      month: '2-digit',
+      year: 'numeric',
+    };
+  },
+  currencyFormatOptions: function (currency, locale) {
+    return {
+      style: 'currency',
+      currency: currency,
+      currencySign: locale === 'en-US' ? 'accounting' : 'standard',
+      currencyDisplay: locale === 'en-US' ? 'symbol' : 'narrowSymbol',
+    };
+  },
+};
+
+export const createEntry = (date, description, change) =>
+  new LedgerEntry(date, description, change);
+
+export function formatEntries(currency, locale, entries) {
+  let dateFormat = OPTIONS.dateFormatOptions();
+  let currencyFormat = OPTIONS.currencyFormatOptions(currency, locale);
+
+  let rows = entries
+    .sort(
+      (a, b) =>
+        a.date - b.date ||
+        a.change - b.change ||
+        a.description.localeCompare(b.description),
+    )
+    .map((entry) => {
+      let formattedEntry = new FormattedLedgerEntry(
+        entry,
+        locale,
+        dateFormat,
+        currencyFormat,
+      );
+      return formattedEntry.toTableRow();
+    });
+
+  return [OPTIONS.headerRow(locale), ...rows].join('\n');
+}

exercises/practice/ledger/.meta/tests.toml

@@ -0,0 +1,48 @@
+# This is an auto-generated file.
+#
+# Regenerating this file via `configlet sync` will:
+# - Recreate every `description` key/value pair
+# - Recreate every `reimplements` key/value pair, where they exist in problem-specifications
+# - Remove any `include = true` key/value pair (an omitted `include` key implies inclusion)
+# - Preserve any other key/value pair
+#
+# As user-added comments (using the # character) will be removed when this file
+# is regenerated, comments can be added via a `comment` key.
+
+[d131ecae-a30e-436c-b8f3-858039a27234]
+description = "empty ledger"
+
+[ce4618d2-9379-4eca-b207-9df1c4ec8aaa]
+description = "one entry"
+
+[8d02e9cb-e6ee-4b77-9ce4-e5aec8eb5ccb]
+description = "credit and debit"
+
+[502c4106-0371-4e7c-a7d8-9ce33f16ccb1]
+description = "multiple entries on same date ordered by description"
+include = false
+
+[29dd3659-6c2d-4380-94a8-6d96086e28e1]
+description = "final order tie breaker is change"
+
+[9b9712a6-f779-4f5c-a759-af65615fcbb9]
+description = "overlong description is truncated"
+
+[67318aad-af53-4f3d-aa19-1293b4d4c924]
+description = "euros"
+
+[bdc499b6-51f5-4117-95f2-43cb6737208e]
+description = "Dutch locale"
+
+[86591cd4-1379-4208-ae54-0ee2652b4670]
+description = "Dutch locale and euros"
+
+[876bcec8-d7d7-4ba4-82bd-b836ac87c5d2]
+description = "Dutch negative number with 3 digits before decimal point"
+
+[29670d1c-56be-492a-9c5e-427e4b766309]
+description = "American negative number with 3 digits before decimal point"
+
+[9c70709f-cbbd-4b3b-b367-81d7c6101de4]
+description = "multiple entries on same date ordered by description"
+reimplements = "502c4106-0371-4e7c-a7d8-9ce33f16ccb1"

exercises/practice/ledger/.npmrc

@@ -0,0 +1 @@
+audit=false

exercises/practice/ledger/LICENSE

@@ -0,0 +1,21 @@
+MIT License
+
+Copyright (c) 2021 Exercism
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

exercises/practice/ledger/babel.config.js

@@ -0,0 +1,4 @@
+module.exports = {
+  presets: ['@exercism/babel-preset-javascript'],
+  plugins: [],
+};