Resistor Color Trio: extend tests, borrowing from awk (#2162)

* Resistor Color Trio: extend tests, borrowing from awk

* [resistor-color-trio] Update description to mention more unit prefixes

* Drop "ambiguous" values

* Drop reference to larger prefixes

Author: IsaacG

exercises/resistor-color-trio/canonical-data.json

@@ -60,6 +60,66 @@
         "value": 470,
         "unit": "kiloohms"
       }
+    },
+    {
+      "uuid": "5f6404a7-5bb3-4283-877d-3d39bcc33854",
+      "description": "Blue and violet and blue",
+      "property": "label",
+      "input": {
+        "colors": ["blue", "violet", "blue"]
+      },
+      "expected": {
+        "value": 67,
+        "unit": "megaohms"
+      }
+    },
+    {
+      "uuid": "7d3a6ab8-e40e-46c3-98b1-91639fff2344",
+      "description": "Minimum possible value",
+      "property": "label",
+      "input": {
+        "colors": ["black", "black", "black"]
+      },
+      "expected": {
+        "value": 0,
+        "unit": "ohms"
+      }
+    },
+    {
+      "uuid": "ca0aa0ac-3825-42de-9f07-dac68cc580fd",
+      "description": "Maximum possible value",
+      "property": "label",
+      "input": {
+        "colors": ["white", "white", "white"]
+      },
+      "expected": {
+        "value": 99,
+        "unit": "gigaohms"
+      }
+    },
+    {
+      "uuid": "0061a76c-903a-4714-8ce2-f26ce23b0e09",
+      "description": "First two colors make an invalid octal number",
+      "property": "label",
+      "input": {
+        "colors": ["black", "grey", "black"]
+      },
+      "expected": {
+        "value": 8,
+        "unit": "ohms"
+      }
+    },
+    {
+      "uuid": "30872c92-f567-4b69-a105-8455611c10c4",
+      "description": "Ignore extra colors",
+      "property": "label",
+      "input": {
+        "colors": ["blue", "green", "yellow", "orange"]
+      },
+      "expected": {
+        "value": 650,
+        "unit": "kiloohms"
+      }
     }
   ]
 }

exercises/resistor-color-trio/description.md

@@ -46,9 +46,11 @@ So an input of `"orange", "orange", "black"` should return:
 
 > "33 ohms"
 
-When we get more than a thousand ohms, we say "kiloohms".
-That's similar to saying "kilometer" for 1000 meters, and "kilograms" for 1000 grams.
+When we get to larger resistors, a [metric prefix][metric-prefix] is used to indicate a larger magnitude of ohms, such as "kiloohms".
+That is similar to saying "2 kilometers" instead of "2000 meters", or "2 kilograms" for "2000 grams".
 
-So an input of `"orange", "orange", "orange"` should return:
+For example, an input of `"orange", "orange", "orange"` should return:
 
 > "33 kiloohms"
+
+[metric-prefix]: https://en.wikipedia.org/wiki/Metric_prefix