Add a test validating direct and indirect constituents

t/jobs/constituents.nix

@@ -0,0 +1,40 @@
+with import ./config.nix;
+rec {
+  constituentA = mkDerivation {
+    name = "empty-dir-A";
+    builder = ./empty-dir-builder.sh;
+  };
+
+  constituentB = mkDerivation {
+    name = "empty-dir-B";
+    builder = ./empty-dir-builder.sh;
+  };
+
+  direct_aggregate = mkDerivation {
+    name = "direct_aggregate";
+    _hydraAggregate = true;
+    constituents = [
+      constituentA
+    ];
+    builder = ./empty-dir-builder.sh;
+  };
+
+  indirect_aggregate = mkDerivation {
+    name = "indirect_aggregate";
+    _hydraAggregate = true;
+    constituents = [
+      "constituentA"
+    ];
+    builder = ./empty-dir-builder.sh;
+  };
+
+  mixed_aggregate = mkDerivation {
+    name = "mixed_aggregate";
+    _hydraAggregate = true;
+    constituents = [
+      "constituentA"
+      constituentB
+    ];
+    builder = ./empty-dir-builder.sh;
+  };
+}

t/queue-runner/direct-indirect-constituents.t

@@ -0,0 +1,35 @@
+use strict;
+use warnings;
+use Setup;
+use Test2::V0;
+
+my $ctx = test_context();
+
+my $builds = $ctx->makeAndEvaluateJobset(
+    expression => 'constituents.nix',
+);
+
+my $constituentBuildA = $builds->{"constituentA"};
+my $constituentBuildB = $builds->{"constituentB"};
+
+my $eval = $constituentBuildA->jobsetevals->first();
+is($eval->evaluationerror->errormsg, "");
+
+subtest "Verifying the direct aggregate" => sub {
+    my $aggBuild = $builds->{"direct_aggregate"};
+    is($aggBuild->constituents->first()->id, $constituentBuildA->id, "The ID of the constituent is correct");
+};
+
+subtest "Verifying the indirect aggregate" => sub {
+    my $indirectBuild = $builds->{"indirect_aggregate"};
+    is($indirectBuild->constituents->first()->id, $constituentBuildA->id, "The ID of the constituent is correct");
+};
+
+subtest "Verifying a mix of direct and indirect aggregate references" => sub {
+    my $mixedBuild = $builds->{"mixed_aggregate"};
+    my ($constituentA, $constituentB) = $mixedBuild->constituents()->search({}, {order_by => { -asc => "job"} });
+    is($constituentA->id, $constituentBuildA->id, "The ID of the constituent is correct");
+    is($constituentB->id, $constituentBuildB->id, "The ID of the constituent is correct");
+};
+
+done_testing;