format: make groupIterable sort by row

Before, it depended on the elements being passed in ordered by their rows.
Before #3823, the iteration
order was the same as the row order; but with sorting the keys slice (which
determines iteration order) on creation, that was changed.

Now, we'll sort the elements within `groupIterable`.

Fixes #3849.

Signed-off-by: Stephan Renatus <[email protected]>

format/format.go

@@ -810,18 +810,25 @@ func (w *writer) listWriter() entryWriter {
 	}
 }
 
-func groupIterable(elements []interface{}, last *ast.Location) (lines [][]interface{}) {
+// groupIterable will group the `elements` slice into slices according to their
+// location: anything on the same line will be put into a slice.
+func groupIterable(elements []interface{}, last *ast.Location) [][]interface{} {
+	sort.Slice(elements, func(i, j int) bool {
+		return locLess(elements[i], elements[j])
+	})
+	var lines [][]interface{}
 	var cur []interface{}
 	for i, t := range elements {
-		loc := getLoc(t)
+		elem := t
+		loc := getLoc(elem)
 		lineDiff := loc.Row - last.Row
 		if lineDiff > 0 && i > 0 {
 			lines = append(lines, cur)
 			cur = nil
 		}
 
 		last = loc
-		cur = append(cur, t)
+		cur = append(cur, elem)
 	}
 	return append(lines, cur)
 }

format/testfiles/test.rego.formatted

@@ -19,7 +19,10 @@ foo[x] {
 	g(x, "foo") = z
 }
 
-globals = {"fizz": "buzz", "foo": "bar"}
+globals = {
+	"foo": "bar",
+	"fizz": "buzz",
+}
 
 partial_obj["x"] = 1
 

format/testfiles/test_issue_3849.rego

@@ -0,0 +1,33 @@
+package test_issue_3849
+
+test_require_context {
+	require_context("monkey", "eat", "banana") with input as {
+		"principal": {"id": 101, "type": "monkey"},
+		"action": "eat",
+		"entity": {"id": 102, "type": "banana"},
+	}
+}
+
+test_contrived {
+	allow with input as {
+		"a": 101,
+		"b": 101,
+		"z": 101,
+		"y": 101,
+		"x": 101,
+		"w": 101,
+		"v": 101,
+		"u": 101,
+		"t": 101,
+		"s": 101,
+		"r": 101,
+		"q": 101,
+		"p": 101,
+		"o": 101,
+		"n": 101,
+		"j": 101,
+		"k": 101,
+		"l": 101,
+		"m": 101,
+	}
+}

format/testfiles/test_issue_3849.rego.formatted

@@ -0,0 +1,33 @@
+package test_issue_3849
+
+test_require_context {
+	require_context("monkey", "eat", "banana") with input as {
+		"principal": {"id": 101, "type": "monkey"},
+		"action": "eat",
+		"entity": {"id": 102, "type": "banana"},
+	}
+}
+
+test_contrived {
+	allow with input as {
+		"a": 101,
+		"b": 101,
+		"z": 101,
+		"y": 101,
+		"x": 101,
+		"w": 101,
+		"v": 101,
+		"u": 101,
+		"t": 101,
+		"s": 101,
+		"r": 101,
+		"q": 101,
+		"p": 101,
+		"o": 101,
+		"n": 101,
+		"j": 101,
+		"k": 101,
+		"l": 101,
+		"m": 101,
+	}
+}