SERVER-23310 Add aggregation expression $arrayToObject

Signed-off-by: Tess Avitabile <tess.avitabile@mongodb.com>
(cherry picked from commit 5b8b1ca6364342d5a1bf21ec6c707edfae0f3555)

1 files changed, 99 insertions, 0 deletions

diff --git a/jstests/aggregation/expressions/arrayToObject.js b/jstests/aggregation/expressions/arrayToObject.js
new file mode 100644
index 00000000000..9e3b4614665
--- /dev/null
+++ b/jstests/aggregation/expressions/arrayToObject.js
@@ -0,0 +1,99 @@
+// Tests for $arrayToObject aggregation expression.
+(function() {
+    "use strict";
+
+    // For assertErrorCode().
+    load("jstests/aggregation/extras/utils.js");
+
+    let coll = db.array_to_object_expr;
+    coll.drop();
+
+    let array_to_object_expr = {$project: {collapsed: {$arrayToObject: "$expanded"}}};
+
+    // $arrayToObject correctly converts a key-value pairs to an object.
+    assert.writeOK(coll.insert({_id: 0, expanded: [["price", 24], ["item", "apple"]]}));
+    let result = coll.aggregate([{$match: {_id: 0}}, array_to_object_expr]).toArray();
+    assert.eq(result, [{_id: 0, collapsed: {"price": 24, "item": "apple"}}]);
+
+    assert.writeOK(
+        coll.insert({_id: 1, expanded: [{"k": "price", "v": 24}, {"k": "item", "v": "apple"}]}));
+    result = coll.aggregate([{$match: {_id: 1}}, array_to_object_expr]).toArray();
+    assert.eq(result, [{_id: 1, collapsed: {"price": 24, "item": "apple"}}]);
+
+    assert.writeOK(
+        coll.insert({_id: 2, expanded: [{"k": "price", "v": 24}, {"k": "item", "v": "apple"}]}));
+    result =
+        coll.aggregate([
+                {$match: {_id: 2}},
+                {
+                  $project: {
+                      collapsed:
+                          {$arrayToObject: {$zip: {inputs: ["$expanded.k", "$expanded.v"]}}}
+                  }
+                }
+            ])
+            .toArray();
+    assert.eq(result, [{_id: 2, collapsed: {"price": 24, "item": "apple"}}]);
+
+    assert.writeOK(coll.insert({_id: 3, expanded: []}));
+    result = coll.aggregate([{$match: {_id: 3}}, array_to_object_expr]).toArray();
+    assert.eq(result, [{_id: 3, collapsed: {}}]);
+
+    // $arrayToObject outputs null on null-ish types.
+    assert.writeOK(coll.insert({_id: 4}));
+    result = coll.aggregate([{$match: {_id: 4}}, array_to_object_expr]).toArray();
+    assert.eq(result, [{_id: 4, collapsed: null}]);
+
+    assert.writeOK(coll.insert({_id: 5, expanded: null}));
+    result = coll.aggregate([{$match: {_id: 5}}, array_to_object_expr]).toArray();
+    assert.eq(result, [{_id: 5, collapsed: null}]);
+
+    assert.writeOK(coll.insert({_id: 6, expanded: undefined}));
+    result = coll.aggregate([{$match: {_id: 6}}, array_to_object_expr]).toArray();
+    assert.eq(result, [{_id: 6, collapsed: null}]);
+
+    assert.writeOK(coll.insert({_id: 7, expanded: [{"k": "price", "v": 24}, ["item", "apple"]]}));
+    assertErrorCode(coll, [{$match: {_id: 7}}, array_to_object_expr], 40391);
+
+    assert.writeOK(coll.insert({_id: 8, expanded: [["item", "apple"], {"k": "price", "v": 24}]}));
+    assertErrorCode(coll, [{$match: {_id: 8}}, array_to_object_expr], 40396);
+
+    assert.writeOK(coll.insert({_id: 9, expanded: "string"}));
+    assertErrorCode(coll, [{$match: {_id: 9}}, array_to_object_expr], 40386);
+
+    assert.writeOK(coll.insert({_id: 10, expanded: ObjectId()}));
+    assertErrorCode(coll, [{$match: {_id: 10}}, array_to_object_expr], 40386);
+
+    assert.writeOK(coll.insert({_id: 11, expanded: NumberLong(0)}));
+    assertErrorCode(coll, [{$match: {_id: 11}}, array_to_object_expr], 40386);
+
+    assert.writeOK(coll.insert({_id: 12, expanded: [0]}));
+    assertErrorCode(coll, [{$match: {_id: 12}}, array_to_object_expr], 40398);
+
+    assert.writeOK(coll.insert({_id: 13, expanded: [["missing_value"]]}));
+    assertErrorCode(coll, [{$match: {_id: 13}}, array_to_object_expr], 40397);
+
+    assert.writeOK(coll.insert({_id: 14, expanded: [[321, 12]]}));
+    assertErrorCode(coll, [{$match: {_id: 14}}, array_to_object_expr], 40395);
+
+    assert.writeOK(coll.insert({_id: 15, expanded: [["key", "value", "offset"]]}));
+    assertErrorCode(coll, [{$match: {_id: 15}}, array_to_object_expr], 40397);
+
+    assert.writeOK(coll.insert({_id: 16, expanded: {y: []}}));
+    assertErrorCode(coll, [{$match: {_id: 16}}, array_to_object_expr], 40386);
+
+    assert.writeOK(coll.insert({_id: 17, expanded: [{y: "x", x: "y"}]}));
+    assertErrorCode(coll, [{$match: {_id: 17}}, array_to_object_expr], 40393);
+
+    assert.writeOK(coll.insert({_id: 18, expanded: [{k: "missing"}]}));
+    assertErrorCode(coll, [{$match: {_id: 18}}, array_to_object_expr], 40392);
+
+    assert.writeOK(coll.insert({_id: 19, expanded: [{k: 24, v: "string"}]}));
+    assertErrorCode(coll, [{$match: {_id: 19}}, array_to_object_expr], 40394);
+
+    assert.writeOK(coll.insert({_id: 20, expanded: [{y: "ignored", k: "item", v: "pear"}]}));
+    assertErrorCode(coll, [{$match: {_id: 20}}, array_to_object_expr], 40392);
+
+    assert.writeOK(coll.insert({_id: 21, expanded: NaN}));
+    assertErrorCode(coll, [{$match: {_id: 21}}, array_to_object_expr], 40386);
+}());