1 files changed, 82 insertions, 0 deletions
diff --git a/users/sterni/nix/fun/tests/default.nix b/users/sterni/nix/fun/tests/default.nix
new file mode 100644
index 000000000000..6b1e6fcc7b0b
--- /dev/null
+++ b/users/sterni/nix/fun/tests/default.nix
@@ -0,0 +1,82 @@
+{ depot, ... }:
+
+let
+  inherit (depot.nix.runTestsuite)
+    runTestsuite
+    it
+    assertEq
+    ;
+
+  inherit (depot.nix) escapeExecline;
+
+  inherit (depot.users.sterni.nix)
+    fun
+    ;
+
+  hasEllipsisTests = it "checks fun.hasEllipsis" [
+    (assertEq "Malicious string" false
+      (fun.hasEllipsis (builtins.toXML ({ foo, ... }: 12))))
+    (assertEq "No function" false
+      (fun.hasEllipsis 23))
+    (assertEq "No attribute set pattern" false
+      (fun.hasEllipsis (a: a + 2)))
+    (assertEq "No ellipsis" false
+      (fun.hasEllipsis ({ foo, bar }: foo + bar)))
+    (assertEq "Ellipsis" true
+      (fun.hasEllipsis ({ depot, pkgs, ... }: 42)))
+  ];
+
+  argCountTests = it "checks fun.argCount" [
+    (assertEq "builtins.sub has two arguments" 2
+      (fun.argCount builtins.sub))
+    (assertEq "fun.argCount has one argument" 1
+      (fun.argCount fun.argCount))
+    (assertEq "runTestsuite has two arguments" 2
+      (fun.argCount runTestsuite))
+  ];
+
+  applyTests = it "checks that fun.apply is equivalent to calling" [
+    (assertEq "fun.apply builtins.sub" (builtins.sub 23 42)
+      (fun.apply builtins.sub [ 23 42 ]))
+    (assertEq "fun.apply escapeExecline" (escapeExecline [ "foo" [ "bar" ] ])
+      (fun.apply escapeExecline [ [ "foo" [ "bar" ] ] ]))
+  ];
+
+  unapplyTests = it "checks fun.unapply" [
+    (assertEq "fun.unapply 3 accepts 3 args" 3
+      (fun.argCount (fun.unapply 3 fun.id)))
+    (assertEq "fun.unapply 73 accepts 73 args" 73
+      (fun.argCount (fun.unapply 73 fun.id)))
+    (assertEq "fun.unapply 1 accepts 73 args" 1
+      (fun.argCount (fun.unapply 1 fun.id)))
+    (assertEq "fun.unapply collects arguments correctly"
+      (fun.unapply 5 fun.id 1 2 3 4 5)
+      [ 1 2 3 4 5 ])
+    (assertEq "fun.unapply calls the given function correctly" 1
+      (fun.unapply 1 builtins.head 1))
+  ];
+
+  fac' = self: acc: n: if n == 0 then acc else self (n * acc) (n - 1);
+
+  facPlain = fun.fix fac' 1;
+  facOpt = fun.tailCallOpt fac' 1;
+
+  tailCallOptTests = it "checks fun.tailCallOpt" [
+    (assertEq "optimized and unoptimized factorial have the same base case"
+      (facPlain 0)
+      (facOpt 0))
+    (assertEq "optimized and unoptimized factorial have same value for 1"
+      (facPlain 1)
+      (facOpt 1))
+    (assertEq "optimized and unoptimized factorial have same value for 100"
+      (facPlain 100)
+      (facOpt 100))
+  ];
+in
+runTestsuite "nix.fun" [
+  hasEllipsisTests
+  argCountTests
+  applyTests
+  unapplyTests
+  tailCallOptTests
+]