update sparkline script (#334)

fun/spark.nu

@@ -1,23 +1,54 @@
-let TICKS = ([(char -u "2581") 
+let TICKS = [(char -u "2581") 
               (char -u "2582") 
               (char -u "2583") 
               (char -u "2584") 
               (char -u "2585") 
               (char -u "2586") 
               (char -u "2587") 
-              (char -u "2588")])
+              (char -u "2588")]
 
 # send an array into spark and get a sparkline out
 # let v = [2, 250, 670, 890, 2, 430, 11, 908, 123, 57]
 # > spark $v
 # ▁▂▆▇▁▄▁█▁▁
 
-def spark [v: any] {
+# create a small sparkline graph
+def spark [v: list] {
     let min = ($v | math min)
     let max = ($v | math max)
-    let scale = (($max - $min) / 7.)
-    for e in $v {
-        let i = (($e - $min) / $scale | into int)
+    let ratio = (if $max == $min { 1.0 } else { 7.0 / ($max - $min)})
+    $v | each { |e|
+        let i = ((($e - $min) * $ratio) | math round)
         $"($TICKS | get $i)"
     } | str collect
+}
+
+def assert_eq [num: int, expected: string, input: list] {
+    let actual = (spark2 $input)
+    let span = (metadata $expected).span;
+    if $actual != $expected {
+      error make {
+        msg: "Actual != Expected", 
+        label: {
+            text: $"expected ($expected) but got ($actual)", start: $span.start, end: $span.end 
+        } 
+      }
+    } else {
+        print $"Test ($num) (ansi green)passed(ansi reset) ✓"
+    }
+}
+
+def spark2_tests [] {
+    assert_eq 1 "▁" [1.0]
+    assert_eq 2 "▁▁" [1.0, 1.0]
+    assert_eq 3 "▁▁▁▁" [1.0, 1.0, 1.0, 1.0]
+    assert_eq 4 "▁▅▄▇▄█" [1.0, 1.3, 1.2, 1.4, 1.2, 1.5]
+    assert_eq 5 "▁█▅" [-1.0, 1.0, 0.0]
+    assert_eq 6 "▁▂█▅▂" [1.0, 5.0, 22.0, 13.0, 5.0]
+    assert_eq 7 "▁▂▄▅▃█" [0.0, 30.0, 55.0, 80.0, 33.0, 150.0]
+    assert_eq 8 "▁▁▁▁▃▁▁▁▂█" [1.0, 2.0, 3.0, 4.0, 100.0, 5.0, 10.0, 20.0, 50.0, 300.0]
+    assert_eq 9 "▁▄█" [1.0, 50.0, 100.0]
+    assert_eq 10 "▁▄█" [0.1, 5.0, 10.0]
+    assert_eq 11 "▁▃█" [2.0, 4.0, 8.0]
+    # assert_eq 12 "▁█" [2.0, 4.0, 8.0]
 }