document throws, run alejandra

README.md

@@ -18,6 +18,10 @@ Make a test file:
         actual = 2 + 2;
         expected = 5;
     })
+    (it "throws a party" {
+        actual = throw "a party";
+        throws = true;
+    })
 ]
 ```
 

flake.lock

@@ -0,0 +1,24 @@
+{
+  "nodes": {
+    "nixpkgs": {
+      "locked": {
+        "lastModified": 1703013332,
+        "narHash": "sha256-+tFNwMvlXLbJZXiMHqYq77z/RfmpfpiI3yjL6o/Zo9M=",
+        "path": "/nix/store/50bgi74d890mpkp90w1jwc5g0dw4dccr-source",
+        "rev": "54aac082a4d9bb5bbc5c4e899603abfb76a3f6d6",
+        "type": "path"
+      },
+      "original": {
+        "id": "nixpkgs",
+        "type": "indirect"
+      }
+    },
+    "root": {
+      "inputs": {
+        "nixpkgs": "nixpkgs"
+      }
+    }
+  },
+  "root": "root",
+  "version": 7
+}

flake.nix

@@ -1,10 +1,16 @@
 {
   description = "A testing library for nix";
 
-  outputs = { self, nixpkgs }:
+  outputs = {
-    let
+    self,
+    nixpkgs,
+  }: let
     system = "x86_64-linux";
     pkgs = import nixpkgs {inherit system;};
-      testing = import ./testing/. { inherit pkgs; };
+    tix = import ./testing/. {inherit pkgs;};
-    in testing;
+  in
+    tix
+    // {
+      packages.x86_64-linux.test = tix.run [./mytest.nix];
+    };
 }

mytest.nix

@@ -0,0 +1,14 @@
+{it, ...}: [
+  (it "can add numbers" {
+    actual = 2 + 2;
+    expected = 4;
+  })
+  (it "loves big brother" {
+    actual = 2 + 2;
+    expected = 5;
+  })
+  (it "won't throw a party" {
+    actual = "a party";
+    throws = true;
+  })
+]

testing/import.nix

@@ -1,6 +1,7 @@
-path:
+path: let
-let it = import ./it.nix;
+  it = import ./it.nix;
-in builtins.trace ("testing " + builtins.baseNameOf path) {
+in
+  builtins.trace ("testing " + builtins.baseNameOf path) {
     inherit path;
-  results = (import path { inherit it; });
+    results = import path {inherit it;};
   }

testing/it.nix

@@ -1,41 +1,51 @@
-msg:
+msg: {
-{ actual, expected ? { }, asString ? false, asJSON ? false
+  actual,
-, removeDunders ? false, safeToPrint ? true, throws ? false }:
+  expected ? {},
-let
+  asString ? false,
+  asJSON ? false,
+  removeDunders ? false,
+  safeToPrint ? true,
+  throws ? false,
+}: let
   preProcess = v:
-    if removeDunders then
+    if removeDunders
-      undunder v
+    then undunder v
-    else if asString then
+    else if asString
-      toString v
+    then toString v
-    else if asJSON then
+    else if asJSON
-      builtins.toJSON v
+    then builtins.toJSON v
-    else
+    else v;
-      v;
 
   a = preProcess actual;
   e = preProcess expected;
 
   undunder = v:
-    if builtins.isAttrs v then
+    if builtins.isAttrs v
-      builtins.removeAttrs v [ "__toString" "__functor" ]
+    then builtins.removeAttrs v ["__toString" "__functor"]
-    else
+    else v;
-      v;
 
-  out = (if safeToPrint then
+  out =
-    builtins.toJSON (undunder (if throws then
+    if safeToPrint
-      (builtins.tryEval actual).value
+    then
+      builtins.toJSON (undunder (
+        if throws
+        then (builtins.tryEval actual).value
         else {
           inherit actual expected;
-    }))
+        }
-  else
+      ))
-    ''{"msg": "cannot be stringified ):"}'');
+    else ''{"msg": "cannot be stringified ):"}'';
 
   success =
-    if throws then (builtins.tryEval actual).success == false else (a == e);
+    if throws
-
+    then (builtins.tryEval actual).success == false
-in {
+    else (a == e);
+in
+  {
     inherit success msg;
-} // (if success then
+  }
-  { }
+  // (
-else
+    if success
-  builtins.trace "FAILED ${msg}" { inherit actual expected; })
+    then {}
+    else builtins.trace "FAILED ${msg}" {inherit actual expected;}
+  )

testing/run.nix

@@ -1,5 +1,4 @@
-pkgs: files:
+pkgs: files: let
-let
   test = import ./import.nix;
   res = map test files;
   resFile = builtins.toFile "results" (builtins.toJSON res);

testing/watch.nix

@@ -7,4 +7,3 @@ pkgs.writeShellScriptBin "watch" ''
     pkill ${pname}
   done
 ''
-