array: Add chunkArray (#36)

* array: Add chunkArray
Splits an array into the given maxSize chunks

* Use a more complex array

* make docs

Author: julienduchesne

array.libsonnet

@@ -52,4 +52,18 @@ local d = import 'github.com/jsonnet-libs/docsonnet/doc-util/main.libsonnet';
     for i in std.range(0, std.length(arr) - 1)
     if filter_func(i, arr[i])
   ],
+
+  '#chunkArray':: d.fn(
+    |||
+      `chunkArray` chunks an array into smaller arrays of the given max size.
+    |||,
+    [
+      d.arg('arr', d.T.array),
+      d.arg('maxSize', d.T.number),
+    ]
+  ),
+  chunkArray(arr, maxSize): [
+    arr[i * maxSize:std.min((i + 1) * maxSize, std.length(arr))]
+    for i in std.range(0, std.ceil(std.length(arr) / maxSize) - 1)
+  ],
 }

docs/array.md

@@ -12,11 +12,21 @@ local array = import "github.com/jsonnet-libs/xtd/array.libsonnet"
 
 ## Index
 
+* [`fn chunkArray(arr, maxSize)`](#fn-chunkarray)
 * [`fn filterMapWithIndex(filter_func, map_func, arr)`](#fn-filtermapwithindex)
 * [`fn slice(indexable, index, end='null', step=1)`](#fn-slice)
 
 ## Fields
 
+### fn chunkArray
+
+```ts
+chunkArray(arr, maxSize)
+```
+
+`chunkArray` chunks an array into smaller arrays of the given max size.
+
+
 ### fn filterMapWithIndex
 
 ```ts

test/array_test.jsonnet

@@ -2,6 +2,7 @@ local array = import '../array.libsonnet';
 local test = import 'github.com/jsonnet-libs/testonnet/main.libsonnet';
 
 local arr = std.range(0, 10);
+local mixedArr = ['a', 1, 'b', 2, 'c', 3, 4, 5, 6, 7, 8, 9, 'd', 'e', 'f', 'g', 'h', 'i', 'j'];
 
 test.new(std.thisFile)
 
@@ -81,3 +82,32 @@ test.new(std.thisFile)
     expected=[0, 2, 4],
   )
 )
+
++ test.case.new(
+  name='chunkArray',
+  test=test.expect.eq(
+    actual=array.chunkArray(mixedArr, maxSize=3),
+    expected=[['a', 1, 'b'], [2, 'c', 3], [4, 5, 6], [7, 8, 9], ['d', 'e', 'f'], ['g', 'h', 'i'], ['j']],
+  )
+)
++ test.case.new(
+  name='chunkArray - maxSize is 2',
+  test=test.expect.eq(
+    actual=array.chunkArray(mixedArr, maxSize=2),
+    expected=[['a', 1], ['b', 2], ['c', 3], [4, 5], [6, 7], [8, 9], ['d', 'e'], ['f', 'g'], ['h', 'i'], ['j']],
+  )
+)
++ test.case.new(
+  name='chunkArray - maxSize is larger than array length',
+  test=test.expect.eq(
+    actual=array.chunkArray(mixedArr, maxSize=100),
+    expected=[mixedArr],
+  )
+)
++ test.case.new(
+  name='chunkArray - maxSize is 1',
+  test=test.expect.eq(
+    actual=array.chunkArray(mixedArr, maxSize=1),
+    expected=[['a'], [1], ['b'], [2], ['c'], [3], [4], [5], [6], [7], [8], [9], ['d'], ['e'], ['f'], ['g'], ['h'], ['i'], ['j']],
+  )
+)