fn.nix: pkgFilter rewrite, can now define custom test cases

(may still do some refactoring)

fn.nix

@@ -8,7 +8,7 @@ rec {
   fileContentsOr = a: b: (ifelse
     (pathIsRegularFile a)
     a b);
-  cwd = toString ./.;
+  cwd = builtins.getEnv "PWD";
 
   # lst (string PATH) (string FILETYPE) (bool RETURNFULLPATH)
   lst = { p ? cwd, t ? "regular", b ? false }: (lists.forEach
@@ -25,18 +25,37 @@ rec {
         (hasAttrByPath a d)
         (hasAttr a d)))
     aList);
+
+  # Not sure how list operations are implemented in Nix
+  # This might be a tad bit inefficient.
+  # TODO: look for better implementation (map is a builtin function so checking that probably won't help)
+  # Sequentially checks elements of list (l) for condition (cond) and executes do on first match.
+  meetsConDo = cond: do: l: ifelse (l == []) false
+    (let
+      h = (head l);
+      t = (tail l);
+    in ifelse (cond h) (do h)
+     (meetsConDo (cond) (do) (t)));
   deps = p: ifelse (isAttrs p) (filter (p: isAttrs p)
     (p.buildInputs ++ p.nativeBuildInputs ++ p.propagatedBuildInputs ++ p.propagatedNativeBuildInputs)
   ) [];
   importFilter = l: p: filter (n: elem (nameFromURL (toString n) ".") l) p;
   depsRec = ld: ifelse (ld == []) [] ((toList ld) ++ (depsRec (lists.unique (lists.flatten (map (d: deps d) (toList ld))))));
-  isBroken = p: ifelse ((elem true (hasAttrs [["meta" "broken"]] p)) && (p.meta.broken == true))
-    (warn "Package ${p.name} is marked as broken." true)
-    false;
+  isBroken = p: meetsConDo (s: ((hasAttrByPath s.path p) && (s.check (getAttrFromPath s.path p)))) (s: s.msg)
+  [
+    { path = ["meta" "broken"]; msg = (warn "Package ${p.name} is marked as broken." true); check = m: m; }
+    { path = ["meta" "knownVulnerabilities" ]; msg = (warn "Package ${p.name} has known Vulnerabilities.." true); check = m: m != []; }
+    # not sure if the following test creates false positives (AFAIK every derivation/package needs to have an outPath)
+    # , definitely should catch all corner cases/everything that fails to evaluate.
+    { path = [ "outPath" ]; msg = (warn "Package ${p.name} has no outPath" true); check = m: !(tryEval m).success; }
+  ];
   depsBroken = p: lists.any (p: (isBroken p)) (deps p);
-  # Those two lines are quite magical 🧙
-  depsBrokenRec = p: (b: b == true) (ifelse (depsBroken p) true
-    (map (p: depsBrokenRec p) (deps p)));
+  # No more magic 🧙 here 😢
+  # But at least it now (hopefully) checks ONLY dependencies (and all of them at that).
+  depsBrokenRec = p: (meetsConDo
+    (p: ifelse (depsBroken p) true (depsBrokenRec (deps p)))
+    (p: true) (deps p)
+  );
   pkgFilter = ld: (filter
     (p: (
       ifelse (isBroken p)