Add practice exercise: space-age

config.json

@@ -122,6 +122,14 @@
         "prerequisites": [],
         "difficulty": 2
       },
+      {
+        "slug": "space-age",
+        "name": "Space Age",
+        "uuid": "09b96007-c782-4b5e-b929-48bab73b5f69",
+        "practices": [],
+        "prerequisites": [],
+        "difficulty": 2
+      },
       {
         "slug": "allergies",
         "name": "Allergies",

exercises/practice/space-age/.docs/instructions.md

@@ -0,0 +1,28 @@
+# Instructions
+
+Given an age in seconds, calculate how old someone would be on a planet in our Solar System.
+
+One Earth year equals 365.25 Earth days, or 31,557,600 seconds.
+If you were told someone was 1,000,000,000 seconds old, their age would be 31.69 Earth-years.
+
+For the other planets, you have to account for their orbital period in Earth Years:
+
+| Planet  | Orbital period in Earth Years |
+| ------- | ----------------------------- |
+| Mercury | 0.2408467                     |
+| Venus   | 0.61519726                    |
+| Earth   | 1.0                           |
+| Mars    | 1.8808158                     |
+| Jupiter | 11.862615                     |
+| Saturn  | 29.447498                     |
+| Uranus  | 84.016846                     |
+| Neptune | 164.79132                     |
+
+~~~~exercism/note
+The actual length of one complete orbit of the Earth around the sun is closer to 365.256 days (1 sidereal year).
+The Gregorian calendar has, on average, 365.2425 days.
+While not entirely accurate, 365.25 is the value used in this exercise.
+See [Year on Wikipedia][year] for more ways to measure a year.
+
+[year]: https://en.wikipedia.org/wiki/Year#Summary
+~~~~

exercises/practice/space-age/.docs/introduction.md

@@ -0,0 +1,20 @@
+# Introduction
+
+The year is 2525 and you've just embarked on a journey to visit all planets in the Solar System (Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus and Neptune).
+The first stop is Mercury, where customs require you to fill out a form (bureaucracy is apparently _not_ Earth-specific).
+As you hand over the form to the customs officer, they scrutinize it and frown.
+"Do you _really_ expect me to believe you're just 50 years old?
+You must be closer to 200 years old!"
+
+Amused, you wait for the customs officer to start laughing, but they appear to be dead serious.
+You realize that you've entered your age in _Earth years_, but the officer expected it in _Mercury years_!
+As Mercury's orbital period around the sun is significantly shorter than Earth, you're actually a lot older in Mercury years.
+After some quick calculations, you're able to provide your age in Mercury Years.
+The customs officer smiles, satisfied, and waves you through.
+You make a mental note to pre-calculate your planet-specific age _before_ future customs checks, to avoid such mix-ups.
+
+~~~~exercism/note
+If you're wondering why Pluto didn't make the cut, go watch [this YouTube video][pluto-video].
+
+[pluto-video]: https://www.youtube.com/watch?v=Z_2gbGXzFbs
+~~~~

exercises/practice/space-age/.meta/config.json

@@ -0,0 +1,19 @@
+{
+  "authors": [
+    "jimmytty"
+  ],
+  "files": {
+    "solution": [
+      "space-age.sql"
+    ],
+    "test": [
+      "space-age_test.sql"
+    ],
+    "example": [
+      ".meta/example.sql"
+    ]
+  },
+  "blurb": "Given an age in seconds, calculate how old someone is in terms of a given planet's solar years.",
+  "source": "Partially inspired by Chapter 1 in Chris Pine's online Learn to Program tutorial.",
+  "source_url": "https://pine.fm/LearnToProgram/?Chapter=01"
+}

exercises/practice/space-age/.meta/example.sql

@@ -0,0 +1,21 @@
+DROP TABLE IF EXISTS planets;
+CREATE TEMPORARY TABLE planets (
+  name   TEXT UNIQUE NOT NULL,
+  period REAL        NOT NULL
+);
+INSERT INTO planets (name, period)
+VALUES ('Mercury',   0.2408467 ),
+       ('Venus'  ,   0.61519726),
+       ('Earth'  ,   1.0       ),
+       ('Mars'   ,   1.8808158 ),
+       ('Jupiter',  11.862615  ),
+       ('Saturn' ,  29.447498  ),
+       ('Uranus' ,  84.016846  ),
+       ('Neptune', 164.79132   );
+
+UPDATE "space-age"
+   SET result = ROUND("space-age".seconds / 31557600.0 / planets.period, 2)
+       FROM planets
+ WHERE "space-age".planet = planets.name
+   AND "space-age".result ISNULL
+       ;

exercises/practice/space-age/.meta/tests.toml

@@ -0,0 +1,39 @@
+# 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.
+
+[84f609af-5a91-4d68-90a3-9e32d8a5cd34]
+description = "age on Earth"
+
+[ca20c4e9-6054-458c-9312-79679ffab40b]
+description = "age on Mercury"
+
+[502c6529-fd1b-41d3-8fab-65e03082b024]
+description = "age on Venus"
+
+[9ceadf5e-a0d5-4388-9d40-2c459227ceb8]
+description = "age on Mars"
+
+[42927dc3-fe5e-4f76-a5b5-f737fc19bcde]
+description = "age on Jupiter"
+
+[8469b332-7837-4ada-b27c-00ee043ebcad]
+description = "age on Saturn"
+
+[999354c1-76f8-4bb5-a672-f317b6436743]
+description = "age on Uranus"
+
+[80096d30-a0d4-4449-903e-a381178355d8]
+description = "age on Neptune"
+
+[57b96e2a-1178-40b7-b34d-f3c9c34e4bf4]
+description = "invalid planet causes error"
+include = false
+comment = "error testing omitted on purpose"

exercises/practice/space-age/create_fixture.sql

@@ -0,0 +1,11 @@
+DROP TABLE IF EXISTS "space-age";
+CREATE TABLE "space-age" (
+    planet  TEXT    NOT NULL,
+    seconds INTEGER NOT NULL,
+    result  REAL
+);
+
+.mode csv
+.import ./data.csv "space-age"
+
+UPDATE "space-age" SET result = NULL;

exercises/practice/space-age/create_test_table.sql

@@ -0,0 +1,28 @@
+DROP TABLE IF EXISTS tests;
+CREATE TABLE IF NOT EXISTS tests (
+    -- uuid and description are taken from the test.toml file
+    uuid TEXT PRIMARY KEY,
+    description TEXT NOT NULL,
+    -- The following section is needed by the online test-runner
+    status TEXT DEFAULT 'fail',
+    message TEXT,
+    output TEXT,
+    test_code TEXT,
+    task_id INTEGER DEFAULT NULL,
+    -- Here are columns for the actual tests
+    planet   TEXT    NOT NULL,
+    seconds  INTEGER NOT NULL,
+    expected REAL
+);
+
+INSERT INTO tests (uuid, description, planet, seconds, expected)
+    VALUES
+        ('84f609af-5a91-4d68-90a3-9e32d8a5cd34','age on Earth','Earth',1000000000,31.69),
+        ('ca20c4e9-6054-458c-9312-79679ffab40b','age on Mercury','Mercury',2134835688,280.88),
+        ('502c6529-fd1b-41d3-8fab-65e03082b024','age on Venus','Venus',189839836,9.78),
+        ('9ceadf5e-a0d5-4388-9d40-2c459227ceb8','age on Mars','Mars',2129871239,35.88),
+        ('42927dc3-fe5e-4f76-a5b5-f737fc19bcde','age on Jupiter','Jupiter',901876382,2.41),
+        ('8469b332-7837-4ada-b27c-00ee043ebcad','age on Saturn','Saturn',2000000000,2.15),
+        ('999354c1-76f8-4bb5-a672-f317b6436743','age on Uranus','Uranus',1210123456,0.46),
+        ('80096d30-a0d4-4449-903e-a381178355d8','age on Neptune','Neptune',1821023456,0.35);
+

exercises/practice/space-age/data.csv

@@ -0,0 +1,8 @@
+"Earth",1000000000,""
+"Mercury",2134835688,""
+"Venus",189839836,""
+"Mars",2129871239,""
+"Jupiter",901876382,""
+"Saturn",2000000000,""
+"Uranus",1210123456,""
+"Neptune",1821023456,""

exercises/practice/space-age/space-age.sql

@@ -0,0 +1,7 @@
+-- Schema: CREATE TABLE "space-age" (
+--             planet  TEXT    NOT NULL,
+--             seconds INTEGER NOT NULL,
+--             result  REAL
+--         );
+-- Task: update the space-age table and set the result based on planet
+--       and seconds.

exercises/practice/space-age/space-age_test.sql

@@ -0,0 +1,43 @@
+-- Create database:
+.read ./create_fixture.sql
+
+-- Read user student solution and save any output as markdown in user_output.md:
+.mode markdown
+.output user_output.md
+.read ./space-age.sql
+.output
+
+-- Create a clean testing environment:
+.read ./create_test_table.sql
+
+-- Comparison of user input and the tests updates the status for each test:
+UPDATE tests
+SET status = 'pass'
+FROM (SELECT planet, seconds, result FROM "space-age") AS actual
+WHERE (actual.planet, actual.seconds, JSON(actual.result)) = (tests.planet, tests.seconds, JSON(tests.expected));
+
+-- Update message for failed tests to give helpful information:
+UPDATE tests
+SET message = (
+    'Result for "'
+    || JSON_OBJECT(
+         'planet',  tests.planet,
+         'seconds', tests.seconds
+       )
+    || '"'
+    || ' is <' || COALESCE(actual.result, 'NULL')
+    || '> but should be <' || tests.expected || '>'
+)
+FROM (SELECT planet, seconds, result FROM "space-age") AS actual
+WHERE (actual.planet, actual.seconds) = (tests.planet, tests.seconds) AND tests.status = 'fail';
+
+-- Save results to ./output.json (needed by the online test-runner)
+.mode json
+.once './output.json'
+SELECT description, status, message, output, test_code, task_id
+FROM tests;
+
+-- Display test results in readable form for the student:
+.mode table
+SELECT description, status, message
+FROM tests;