Add resistor-color (#286)

* Add resistor-color

* Remove colors from stub

config.json

@@ -626,6 +626,14 @@
         "prerequisites": [],
         "difficulty": 1
       },
+      {
+        "slug": "resistor-color",
+        "name": "Resistor Color",
+        "uuid": "b72f816f-8d3a-48c1-b3e7-ad313354a8ca",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "eliuds-eggs",
         "name": "Eliud's Eggs",

exercises/practice/resistor-color/.docs/instructions.md

@@ -0,0 +1,39 @@
+# Instructions
+
+If you want to build something using a Raspberry Pi, you'll probably use _resistors_.
+For this exercise, you need to know two things about them:
+
+- Each resistor has a resistance value.
+- Resistors are small - so small in fact that if you printed the resistance value on them, it would be hard to read.
+
+To get around this problem, manufacturers print color-coded bands onto the resistors to denote their resistance values.
+Each band has a position and a numeric value.
+
+The first 2 bands of a resistor have a simple encoding scheme: each color maps to a single number.
+
+In this exercise you are going to create a helpful program so that you don't have to remember the values of the bands.
+
+These colors are encoded as follows:
+
+- Black: 0
+- Brown: 1
+- Red: 2
+- Orange: 3
+- Yellow: 4
+- Green: 5
+- Blue: 6
+- Violet: 7
+- Grey: 8
+- White: 9
+
+The goal of this exercise is to create a way:
+
+- to look up the numerical value associated with a particular color band
+- to list the different band colors
+
+Mnemonics map the colors to the numbers, that, when stored as an array, happen to map to their index in the array:
+Better Be Right Or Your Great Big Values Go Wrong.
+
+More information on the color encoding of resistors can be found in the [Electronic color code Wikipedia article][e-color-code].
+
+[e-color-code]: https://en.wikipedia.org/wiki/Electronic_color_code

exercises/practice/resistor-color/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "BNAndras"
+  ],
+  "files": {
+    "solution": [
+      "resistor_color.bal"
+    ],
+    "test": [
+      "tests/resistor_color_test.bal"
+    ],
+    "example": [
+      ".meta/reference/resistor_color.bal"
+    ]
+  },
+  "blurb": "Convert a resistor band's color to its numeric representation.",
+  "source": "Maud de Vries, Erik Schierboom",
+  "source_url": "https://github.com/exercism/problem-specifications/issues/1458"
+}

exercises/practice/resistor-color/.meta/reference/resistor_color.bal

@@ -0,0 +1,26 @@
+final string[] colorList = [
+    "black",
+    "brown",
+    "red",
+    "orange",
+    "yellow",
+    "green",
+    "blue",
+    "violet",
+    "grey",
+    "white"
+];
+
+# Calculates the resistor value for the passed band color
+# 
+# + color - The color of the resistor band
+# + return - The value of the resistor band
+function colorCode(string color) returns int {
+    return colorList.indexOf(color) ?: 0;
+}
+
+# Returns the list of colors in the resistor color code
+# + return - The list of colors
+function colors() returns string[] {
+   return colorList;
+}

exercises/practice/resistor-color/.meta/tests.toml

@@ -0,0 +1,22 @@
+# 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.
+
+[49eb31c5-10a8-4180-9f7f-fea632ab87ef]
+description = "Color codes -> Black"
+
+[0a4df94b-92da-4579-a907-65040ce0b3fc]
+description = "Color codes -> White"
+
+[5f81608d-f36f-4190-8084-f45116b6f380]
+description = "Color codes -> Orange"
+
+[581d68fa-f968-4be2-9f9d-880f2fb73cf7]
+description = "Colors"

exercises/practice/resistor-color/Ballerina.toml

@@ -0,0 +1,5 @@
+[package]
+org = "ballerina_exercism"
+name = "resistor_color"
+version = "0.1.0"
+distribution = "2201.5.0"

exercises/practice/resistor-color/Dependencies.toml

@@ -0,0 +1,38 @@
+# AUTO-GENERATED FILE. DO NOT MODIFY.
+
+# This file is auto-generated by Ballerina for managing dependency versions.
+# It should not be modified by hand.
+
+[ballerina]
+dependencies-toml-version = "2"
+distribution-version = "2201.5.0"
+
+[[package]]
+org = "ballerina"
+name = "jballerina.java"
+version = "0.0.0"
+scope = "testOnly"
+
+[[package]]
+org = "ballerina"
+name = "test"
+version = "0.0.0"
+scope = "testOnly"
+dependencies = [
+	{org = "ballerina", name = "jballerina.java"}
+]
+modules = [
+	{org = "ballerina", packageName = "test", moduleName = "test"}
+]
+
+[[package]]
+org = "ballerina_exercism"
+name = "resistor_color"
+version = "0.1.0"
+dependencies = [
+	{org = "ballerina", name = "test"}
+]
+modules = [
+	{org = "ballerina_exercism", packageName = "resistor_color", moduleName = "resistor_color"}
+]
+

exercises/practice/resistor-color/resistor_color.bal

@@ -0,0 +1,13 @@
+# Calculates the resistor value for the passed band color
+# 
+# + color - The color of the resistor band
+# + return - The value of the resistor band
+function colorCode(string color) returns int {
+    // TODO: implement this function
+}
+
+# Returns the list of colors in the resistor color code
+# + return - The list of colors
+function colors() returns string[] {
+    // TODO: implement this function
+}

exercises/practice/resistor-color/tests/resistor_color_test.bal

@@ -0,0 +1,39 @@
+import ballerina/test;
+
+@test:Config {}
+function testBlack() {
+    test:assertEquals(0, colorCode("black"));
+}
+
+@test:Config {
+    enable: false
+}
+function testWhite() {
+    test:assertEquals(9, colorCode("white"));
+}
+
+@test:Config {
+    enable: false
+}
+function testOrange() {
+    test:assertEquals(3, colorCode("orange"));
+}
+
+@test:Config {
+    enable: false
+}
+function testColors() {
+    string[] expected = [
+        "black",
+        "brown",
+        "red",
+        "orange",
+        "yellow",
+        "green",
+        "blue",
+        "violet",
+        "grey",
+        "white"
+    ];
+    test:assertEquals(expected, colors());
+}