[New Exercise]: Ledger (#317)

* [New Exercise]: Ledger

* Update Ledger.ps1

Update base file to pass all tests

* Update Ledger.ps1

change from using culture to simply currency format

* update example file

* Update Ledger.example.ps1

config.json

@@ -1000,6 +1000,14 @@
         "prerequisites": [],
         "difficulty": 5
       },
+      {
+        "slug": "ledger",
+        "name": "Ledger",
+        "uuid": "20bad781-7c4b-4133-8ce3-2160ab12a3a0",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 5
+      },
       {
         "slug": "rectangles",
         "name": "Rectangles",

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/.meta/Ledger.example.ps1

@@ -0,0 +1,130 @@
+<#
+.SYNOPSIS
+    Refactor a ledger printer.
+
+.DESCRIPTION
+    The code below is an attempt of creating a printer for a ledger.
+    It barely works (only passed some of the tests), and is generally quite messy.
+    Your job here is to refactor the code.
+
+.EXAMPLE
+    $entry1 = CreateEntry -Date '2011-12-13' -Desc 'Birthday present' -Amount 1234
+    $entry2 = CreateEntry -Date '2011-11-19' -Desc 'Party prep & catering services' -Amount 98765
+    FormatEntries -Currency "EUR" -Locale "en-US" -Entries @($entry1, $entry2)
+
+    Returns:
+    @"
+    Date       | Description               | Change
+    11/19/2011 | Party prep & catering ... |      €987.65
+    12/13/2011 | Birthday present          |       €12.34
+    "@
+#>
+
+Class LedgerEntry{
+    [datetime] $Date
+    [string] $Desc
+    [int] $Change
+
+    LedgerEntry($date, $desc, $change) {
+        $this.Date = $date
+        $this.Desc = $desc
+        $this.Change = $change
+    }
+
+    [string] Format([string] $Currency, [string] $Locale) {
+        $format   = $this.GetFrame($Locale, $this.Change)
+        $dateFormat  = $this.GetDateFormat($Currency, $Locale)
+
+        $dateStr  = $this.Date.ToString($dateFormat)
+        $moneyStr = ($this.Change / 100).ToString("C2", [cultureinfo]::new($Locale))
+
+        if ($Currency -eq "EUR" -and $Locale -eq "en-US") {
+            $moneyStr = $moneyStr -replace '\$', '€'
+        }
+        if ($Currency -eq "USD" -and $Locale -eq "nl-NL") {
+            $moneyStr = $moneyStr -replace '€', '$'
+        }
+        if ($this.Desc.Length -gt 25) {
+            $this.Desc = $this.Desc.Substring(0,22) + "..."
+        }
+        return $format -f @($dateStr, $this.Desc, $moneyStr)
+    }
+
+    [string] hidden GetFrame([string] $Locale, [int] $Change) {
+        if ($Locale -eq "nl-NL" -or $Change -ge 0) {
+            return "{0,-10} | {1,-25} | {2,12} "
+        }
+        return "{0,-10} | {1,-25} | {2,13}"
+    }
+
+    [object] hidden GetDateFormat([string] $Currency, [string] $Locale) {
+        $dateFrm = switch ($Locale) {
+            "en-US" { "MM\/dd\/yyyy" }
+            "nl-NL" { "dd-MM-yyyy" }
+            Default {Throw "Locale not supported"}
+        }
+        return $dateFrm
+    }
+
+    [string] static Header($Locale) {
+        $format = "{0,-10} | {1,-25} | {2,-13}"
+        $info = switch ($Locale) {
+            "en-US" { @("Date", "Description", "Change")  }
+            "nl-NL" { @("Datum", "Omschrijving", "Verandering") }
+            Default {Throw "Locale not supported"}
+        }
+        return $format -f $info
+    }
+}
+
+Function CreateEntry {
+    <#
+    .DESCRIPTION
+    A function to create an entry for the ledger.
+    This function is required for the test suite.
+
+    .PARAMETER Date
+    String represent the date.
+
+    .PARAMETER Desc
+    String represent the description of the entry.
+
+    .PARAMETER Amount
+    Integer represent the amount of money in cents.
+    #>
+    param (
+        [string] $Date,
+        [string] $Desc,
+        [int] $Amount
+    )
+    [LedgerEntry]::new($Date, $Desc, $Amount)
+}
+
+Function FormatEntries {
+    <#
+    .DESCRIPTION
+    A function to formats the entries of the ledger based on other info.
+    This function is required for the test suite.
+
+    .PARAMETER Currency
+    String represent the currency symbol.
+
+    .PARAMETER Locale
+    String represent the region and culture to be followed.
+
+    .PARAMETER Entries
+    Array of entries, each is an instance of the class LedgerEntry, created via CreateEntry function.
+    #>
+    param (
+        [string] $Currency,
+        [string] $Locale,
+        [LedgerEntry[]] $Entries
+    )
+    $table = @()
+    $table += [LedgerEntry]::Header($Locale)
+    $Entries = $Entries | Sort-Object Date, Desc, Change
+    foreach ($entry in $Entries) {
+        $table += $entry.Format($Currency, $Locale)
+    }
+    $table -join "`n"
+}

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

@@ -0,0 +1,17 @@
+{
+  "authors": [
+    "glaxxie"
+  ],
+  "files": {
+    "solution": [
+      "Ledger.ps1"
+    ],
+    "test": [
+      "Ledger.tests.ps1"
+    ],
+    "example": [
+      ".meta/Ledger.example.ps1"
+    ]
+  },
+  "blurb": "Refactor a ledger printer."
+}

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

@@ -0,0 +1,43 @@
+# 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"
+
+[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"