Merge branch 'feat/autodiscovery' into 'main'

feat: add autodiscovery block

See merge request rensa-nix/core!3

CHANGELOG.md

@@ -2,6 +2,14 @@
 All notable changes to this project will be documented in this file. See [conventional commits](https://www.conventionalcommits.org/) for commit guidelines.
 
 - - -
+## [v0.1.1](https://gitlab.com/rensa-nix/core/compare/558066d8df65242b6e1c7b6fcb62a0a3cf794899..v0.1.1) - 2025-12-23
+#### Bug Fixes
+- (**loader**) infinite recursion error when accessing sibling blocks - ([0d6970d](https://gitlab.com/rensa-nix/core/commit/0d6970d95ae3f5e20046b2cb0ec88d396cc55d9e)) - [@TECHNOFAB](https://gitlab.com/TECHNOFAB)
+#### Miscellaneous Chores
+- add LICENSE - ([558066d](https://gitlab.com/rensa-nix/core/commit/558066d8df65242b6e1c7b6fcb62a0a3cf794899)) - [@TECHNOFAB](https://gitlab.com/TECHNOFAB)
+
+- - -
+
 ## [v0.1.0](https://gitlab.com/rensa-nix/core/compare/3aeff518bb9ebf0918a0bb013d66ee56fa415033..v0.1.0) - 2025-12-20
 #### Features
 - (**builder**) default to systems from inputs if exists - ([9ea903d](https://gitlab.com/rensa-nix/core/commit/9ea903dde6de65c85532995e5872ad7d2e6e6f5f)) - [@TECHNOFAB](https://gitlab.com/TECHNOFAB)

LICENSE.md

@@ -0,0 +1,7 @@
+Copyright 2025 TECHNOFAB
+
+Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the “Software”), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED “AS IS”, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.

cells/repo/ci.nix

@@ -3,8 +3,19 @@
 in
   cilib.mkCI {
     pipelines."default" = {
-      stages = ["build" "deploy"];
+      stages = ["test" "build" "deploy"];
       jobs = {
+        "test:lib" = {
+          stage = "test";
+          script = [
+            "nix run .#tests -- --junit=junit.xml"
+          ];
+          allow_failure = true;
+          artifacts = {
+            when = "always";
+            reports.junit = "junit.xml";
+          };
+        };
         "docs" = {
           stage = "build";
           script = [

cells/repo/docs.nix

@@ -36,6 +36,7 @@ in
           {"API Reference" = "api.md";}
           {"Related Libraries" = "libraries.md";}
           {"Direnv Integration" = "direnv.md";}
+          {"Debugging" = "debugging.md";}
         ];
         markdown_extensions = [
           {

cells/repo/flake.lock

@@ -3,11 +3,11 @@
     "devshell": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1758204313,
+        "lastModified": 1767218348,
-        "narHash": "sha256-ainbY0Oajb1HMdvy+A8QxF/P5qwcbEzJGEY5pzKdDdc=",
+        "narHash": "sha256-8MJqwH9sRMuHH+RsB7iqWyWD30TgmpiYKEvegAULggs=",
         "owner": "rensa-nix",
         "repo": "devshell",
-        "rev": "7d0c4bc78d9f017a739b0c7eb2f4e563118353e6",
+        "rev": "7a9b7e5d9f162a1fa3edfdc0169cdc29d3a67f8e",
         "type": "gitlab"
       },
       "original": {
@@ -20,11 +20,11 @@
     "devtools-lib": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1766237846,
+        "lastModified": 1767214272,
-        "narHash": "sha256-7n3WFabnf49SFHXD/e4zfLit3BniZZOecUXfBm3d1d0=",
+        "narHash": "sha256-gvW7flZ60xdv3Z3Ksec5jcRjW2sqRHsGoJdwsNWQVPk=",
         "owner": "rensa-nix",
         "repo": "devtools",
-        "rev": "5c8712f48c5bcb6b79d3da1afd1268f84f5e35e3",
+        "rev": "f40e59c32c48cdbf4cbc621c2f0f11e7bb80dbd3",
         "type": "gitlab"
       },
       "original": {
@@ -55,11 +55,11 @@
     "nixmkdocs": {
       "locked": {
         "dir": "lib",
-        "lastModified": 1766062227,
+        "lastModified": 1766404754,
-        "narHash": "sha256-jhr5CUi9eDeMIAJn7ayXP8Wr+Y2loV5EhdDIKDkRIdw=",
+        "narHash": "sha256-EjBe6x6BT8ckPirMWhSf1GfaFxORYxR/Uu71FvSAm60=",
         "owner": "TECHNOFAB",
         "repo": "nixmkdocs",
-        "rev": "cb0bb5dc3382e8ba5d81324a2f1fd94ccd5a5df4",
+        "rev": "cfa9606eeeb9288e2799896d7d42b3d3860f9ccb",
         "type": "gitlab"
       },
       "original": {
@@ -69,12 +69,31 @@
         "type": "gitlab"
       }
     },
+    "nixtest-lib": {
+      "locked": {
+        "dir": "lib",
+        "lastModified": 1765728058,
+        "narHash": "sha256-V3FXECl1oTxEtGteNz3o3GJs/X8asSn1TxRpZ2F+htU=",
+        "owner": "TECHNOFAB",
+        "repo": "nixtest",
+        "rev": "2477ad31ae3aa4134e1bb5eeddbebe0cb64ccb57",
+        "type": "gitlab"
+      },
+      "original": {
+        "dir": "lib",
+        "owner": "TECHNOFAB",
+        "ref": "v1.2.1",
+        "repo": "nixtest",
+        "type": "gitlab"
+      }
+    },
     "root": {
       "inputs": {
         "devshell": "devshell",
         "devtools-lib": "devtools-lib",
         "nix-gitlab-ci-lib": "nix-gitlab-ci-lib",
         "nixmkdocs": "nixmkdocs",
+        "nixtest-lib": "nixtest-lib",
         "soonix-lib": "soonix-lib",
         "treefmt-nix": "treefmt-nix"
       }
@@ -99,11 +118,11 @@
     "treefmt-nix": {
       "flake": false,
       "locked": {
-        "lastModified": 1766000401,
+        "lastModified": 1767122417,
-        "narHash": "sha256-+cqN4PJz9y0JQXfAK5J1drd0U05D5fcAGhzhfVrDlsI=",
+        "narHash": "sha256-yOt/FTB7oSEKQH9EZMFMeuldK1HGpQs2eAzdS9hNS/o=",
         "owner": "numtide",
         "repo": "treefmt-nix",
-        "rev": "42d96e75aa56a3f70cab7e7dc4a32868db28e8fd",
+        "rev": "dec15f37015ac2e774c84d0952d57fcdf169b54d",
         "type": "github"
       },
       "original": {

cells/repo/flake.nix

@@ -5,6 +5,7 @@
     soonix-lib.url = "gitlab:TECHNOFAB/soonix?dir=lib";
     nix-gitlab-ci-lib.url = "gitlab:TECHNOFAB/nix-gitlab-ci/3.1.2?dir=lib";
     devtools-lib.url = "gitlab:rensa-nix/devtools?dir=lib";
+    nixtest-lib.url = "gitlab:TECHNOFAB/nixtest/v1.2.1?dir=lib";
     treefmt-nix = {
       url = "github:numtide/treefmt-nix";
       flake = false;
@@ -18,6 +19,8 @@
       doclib = i.nixmkdocs.lib {inherit (i.parent) pkgs;};
       soonix = i.soonix-lib.lib {inherit (i.parent) pkgs;};
       cilib = i.nix-gitlab-ci-lib.lib {inherit (i.parent) pkgs;};
+      ntlib = i.nixtest-lib.lib {inherit (i.parent) pkgs;};
+      rensa = import "${i.parent.self}/lib" {inherit (i.parent.pkgs) lib;};
       treefmt = import i.treefmt-nix;
     };
 }

cells/repo/tests.nix

@@ -0,0 +1,10 @@
+{inputs, ...}: let
+  inherit (inputs) pkgs ntlib rensa;
+in {
+  tests = ntlib.mkNixtest {
+    modules = ntlib.autodiscover {dir = "${inputs.self}/tests";};
+    args = {
+      inherit pkgs ntlib rensa;
+    };
+  };
+}

cells/test/other.nix

@@ -0,0 +1,4 @@
+# test to make sure infinite recursion doesn't happen when accessing sibling blocks
+# run `nix eval .#<system>.test` to check
+# should return { other = { hello = "world"; }; test = «repeated»; }
+{cell, ...}: cell.test

docs/api.md

@@ -8,7 +8,7 @@ The main entry point for creating a Rensa flake.
 
 - `inputs`: The flake inputs.
 - `cellsFrom`: Path to the directory containing your cells.
-- `cellBlocks`: A list of blocks to load for each cell.
+- `cellBlocks`: A list of blocks to load for each cell. Defaults to `[rensa.blocks.autodiscover]`.
 - `transformInputs` (optional): A function to transform inputs before they are passed to cells.
 
 ### Returns
@@ -23,7 +23,7 @@ The underlying builder function used by `buildWith`. It returns the raw Rensa ou
 
 - `inputs`: The flake inputs.
 - `cellsFrom`: Path to the directory containing your cells.
-- `cellBlocks`: A list of blocks to load for each cell.
+- `cellBlocks`: A list of blocks to load for each cell. Defaults to `[rensa.blocks.autodiscover]`.
 - `transformInputs` (optional): A function to transform inputs.
 
 ### Returns
@@ -56,6 +56,45 @@ by passing through actions etc. from a cell.
 
 Currently not really used.
 
+### `autodiscover`
+
+```nix
+autodiscover
+# or
+(autodiscover "cellName")
+```
+
+Automatically discovers and loads all cell blocks by scanning the cells directory for `.nix` files.
+When `autodiscover` is present in `cellBlocks`, Rensa will:
+
+1. Walk through all cells in `cellsFrom` (or specific cell if provided).
+1. Find all `.nix` files (excluding `flake.nix`).
+1. Find all directories containing `default.nix`.
+1. Generate `simple` block definitions for each discovered block.
+
+**Usage patterns:**
+
+```nix
+# full autodiscovery
+cellBlocks = with rensa.blocks; [
+  autodiscover
+];
+# or
+cellBlocks = with rensa.blocks; [
+  (autodiscover "backend")  # only discover blocks from backend cell
+  (autodiscover "frontend") # only discover blocks from frontend cell
+];
+# mixed
+cellBlocks = with rensa.blocks; [
+  (simple "myBlock")  # explicit block (takes precedence)
+  autodiscover        # discover all others
+];
+```
+
+!!! note
+
+    When a block is both explicitly defined and discovered, the explicit definition takes precedence.
+
 ## `rensa.select`
 
 Helper to select specific outputs from the generated flake.

docs/debugging.md

@@ -0,0 +1,38 @@
+# Debugging
+
+## Error Context
+
+To help with debugging, Rensa uses Nix's `builtins.addErrorContext` to add context
+about where an error is happening.
+
+Use the following command to get just these logs from Rensa and please include that (or the whole stacktrace) in any issues or bug reports :)
+
+```sh
+nix ... --show-trace 2> >(grep "… \[ren\]")
+```
+
+## Trace Verbose
+
+There are also some `traceVerbose` calls in Rensa, so to debug non-failing executions
+just run Nix with the `--trace-verbose` flag.
+
+The output could look like this (example with this repo's flake):
+
+```sh
+trace: [ren] loading cell block ci, type ci, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system aarch64-darwin
+trace: [ren] loading cell block devShells, type devShells, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system aarch64-darwin
+trace: [ren] loading cell block docs, type docs, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system aarch64-darwin
+trace: [ren] loading cell block soonix, type soonix, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system aarch64-darwin
+trace: [ren] loading cell block ci, type ci, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system aarch64-linux
+trace: [ren] loading cell block devShells, type devShells, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system aarch64-linux
+trace: [ren] loading cell block docs, type docs, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system aarch64-linux
+trace: [ren] loading cell block soonix, type soonix, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system aarch64-linux
+trace: [ren] loading cell block ci, type ci, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system x86_64-darwin
+trace: [ren] loading cell block devShells, type devShells, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system x86_64-darwin
+trace: [ren] loading cell block docs, type docs, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system x86_64-darwin
+trace: [ren] loading cell block soonix, type soonix, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system x86_64-darwin
+trace: [ren] loading cell block ci, type ci, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system x86_64-linux
+trace: [ren] loading cell block devShells, type devShells, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system x86_64-linux
+trace: [ren] loading cell block docs, type docs, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system x86_64-linux
+trace: [ren] loading cell block soonix, type soonix, from cell /nix/store/7acz6q9360fkg0x187yx43d1vwpv850l-cells/repo, for system x86_64-linux
+```

flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs": {
       "locked": {
-        "lastModified": 1766125104,
+        "lastModified": 1767151656,
-        "narHash": "sha256-l/YGrEpLromL4viUo5GmFH3K5M1j0Mb9O+LiaeCPWEM=",
+        "narHash": "sha256-ujL2AoYBnJBN262HD95yer7QYUmYp5kFZGYbyCCKxq8=",
         "owner": "nixos",
         "repo": "nixpkgs",
-        "rev": "7d853e518814cca2a657b72eeba67ae20ebf7059",
+        "rev": "f665af0cdb70ed27e1bd8f9fdfecaf451260fc55",
         "type": "github"
       },
       "original": {
@@ -18,11 +18,11 @@
     },
     "nixpkgs-lib": {
       "locked": {
-        "lastModified": 1765674936,
+        "lastModified": 1766884708,
-        "narHash": "sha256-k00uTP4JNfmejrCLJOwdObYC9jHRrr/5M/a/8L2EIdo=",
+        "narHash": "sha256-x8nyRwtD0HMeYtX60xuIuZJbwwoI7/UKAdCiATnQNz0=",
         "owner": "nix-community",
         "repo": "nixpkgs.lib",
-        "rev": "2075416fcb47225d9b68ac469a5c4801a9c4dd85",
+        "rev": "15177f81ad356040b4460a676838154cbf7f6213",
         "type": "github"
       },
       "original": {

flake.nix

@@ -19,16 +19,19 @@
       cellsFrom = ./cells;
       cellBlocks = with rensa.blocks; [
         (simple "test")
+        (simple "other")
         (simple "devShells")
         (simple "docs")
         (simple "ci")
         (simple "soonix")
+        (simple "tests")
       ];
     } {
       packages = rensa.select inputs.self [
         ["repo" "docs"]
         ["repo" "ci" "packages"]
         ["repo" "soonix" "packages"]
+        ["repo" "tests"]
       ];
     };
 }

lib/blocks/default.nix

@@ -6,6 +6,17 @@
   dynamic = name: {
     inherit name;
     type = name;
+    cli = true;
+    actions = args: {};
     # TODO: dynamic actions
   };
+  autodiscover = {
+    name = "__autodiscover";
+    type = "__autodiscover";
+    _functor = self: cell:
+      self
+      // {
+        inherit cell;
+      };
+  };
 }

lib/core/autodiscover.nix

@@ -0,0 +1,98 @@
+{
+  l,
+  cellsFrom,
+  cellBlocks,
+}: let
+  # find autodiscover blocks
+  autodiscoverBlocks = l.filter (block: block.name or "" == "__autodiscover") cellBlocks;
+  explicitBlocks = l.filter (block: block.name or "" != "__autodiscover") cellBlocks;
+  hasAutodiscover = (l.length autodiscoverBlocks) > 0;
+
+  # discover all block names from a single cell's directory
+  discoverBlocksFromCell = cellPath: let
+    cellContents = l.readDir cellPath;
+    # filter for .nix files (but not flake.nix) and dirs with default.nix
+    blockNames = l.unique (
+      l.filter (name: name != null) (
+        l.mapAttrsToList (
+          name: type:
+            if type == "regular" && l.hasSuffix ".nix" name && name != "flake.nix"
+            then l.removeSuffix ".nix" name
+            else if type == "directory" && l.pathExists (cellPath + "/${name}/default.nix")
+            then name
+            else null
+        )
+        cellContents
+      )
+    );
+  in
+    builtins.addErrorContext "[ren] while discovering blocks from cell ${cellPath}"
+    blockNames;
+
+  # discover all blocks from all cells or specific cells
+  discoverAllBlocks = let
+    # check if any autodiscover blocks have cell-specific targets (eg. `autodiscover "a"`)
+    cellSpecificDiscoveries = l.filter (block: block ? cell) autodiscoverBlocks;
+    globalDiscoveries = l.filter (block: !(block ? cell)) autodiscoverBlocks;
+
+    cellSpecificBlocks = l.flatten (
+      l.map (
+        block: let
+          cellPath = cellsFrom + "/${block.cell}";
+        in
+          if l.pathExists cellPath
+          then discoverBlocksFromCell cellPath
+          else []
+      )
+      cellSpecificDiscoveries
+    );
+
+    # global autodiscover
+    globalBlocks = builtins.addErrorContext "[ren] while discovering global blocks" (
+      if (l.length globalDiscoveries) > 0
+      then let
+        cells = l.readDir cellsFrom;
+        allBlockNames = l.unique (
+          l.flatten (
+            l.mapAttrsToList (
+              cellName: cellType:
+                if cellType == "directory"
+                then discoverBlocksFromCell (cellsFrom + "/${cellName}")
+                else []
+            )
+            cells
+          )
+        );
+      in
+        allBlockNames
+      else []
+    );
+
+    allBlockNames = l.unique (cellSpecificBlocks ++ globalBlocks);
+  in
+    builtins.addErrorContext "[ren] while discovering all blocks"
+    l.map (name: {
+      inherit name;
+      type = name;
+    })
+    allBlockNames;
+
+  discoveredBlocks =
+    if hasAutodiscover
+    then discoverAllBlocks
+    else [];
+
+  # merge the explicit and autodiscovered blocks (explicit taking precedence)
+  allBlocks = explicitBlocks ++ discoveredBlocks;
+  uniqueBlocks =
+    l.foldl' (
+      acc: block:
+      # first occurence of name wins
+        if l.any (b: b.name == block.name) acc
+        then acc
+        else acc ++ [block]
+    ) []
+    allBlocks;
+in
+  builtins.addErrorContext "[ren] while autodiscovering cell blocks"
+  uniqueBlocks

lib/core/builder.nix

@@ -2,6 +2,8 @@
   l,
   utils,
   loader,
+  autodiscover,
+  blocks,
 }: let
   inherit (utils) accumulate;
   inherit (loader) createCellLoader;
@@ -9,7 +11,7 @@
   build = {
     inputs,
     cellsFrom,
-    cellBlocks,
+    cellBlocks ? [blocks.autodiscover],
     transformInputs ? system: i: i,
     ...
   } @ args: let
@@ -28,16 +30,20 @@
         ]
       );
 
+    cellBlocks' = autodiscover {inherit l cellsFrom cellBlocks;};
+
     cells = res.output;
 
     loadOutputFor = system: let
       loadCell = createCellLoader {
-        inherit inputs system cells cellsFrom cellBlocks transformInputs;
+        inherit inputs system cells cellsFrom transformInputs;
+        cellBlocks = cellBlocks';
       };
 
       cells' = l.mapAttrsToList (cell: type: cell) (l.readDir cellsFrom);
       res = accumulate (l.map loadCell cells');
-    in [
+    in
+      builtins.addErrorContext "[ren] while loading output for ${system}" [
         {${system} = res.output;}
         {${system} = res.actions;}
         {
@@ -48,6 +54,7 @@
 
     res = accumulate (l.map loadOutputFor systems);
   in
+    builtins.addErrorContext "[ren] while building rensa output"
     res.output
     // {
       __ren = {
@@ -89,10 +96,12 @@
     recursiveUpdate = lhs: rhs:
       recursiveUpdateUntil g lhs rhs;
   in
+    builtins.addErrorContext "[ren] while building rensa output (buildWith)" (
       build args
       // {
         __functor = l.flip recursiveUpdate;
-    };
+      }
+    );
 in {
   inherit build buildWith;
 }

lib/core/call-flake.nix

@@ -112,4 +112,5 @@ ref: inputOverrides: let
     )
     lockFile.nodes;
 in
+  builtins.addErrorContext "[ren] while loading flake lockfile ${ref}"
   allNodes.${lockFile.root}

lib/core/default.nix

@@ -1,11 +1,13 @@
 {
   l,
   utils,
+  blocks,
 }: let
   paths = import ./paths.nix;
   callFlake = import ./call-flake.nix;
+  autodiscover = import ./autodiscover.nix;
   loader = import ./loader.nix {inherit l utils paths callFlake;};
-  builder = import ./builder.nix {inherit l utils loader;};
+  builder = import ./builder.nix {inherit l utils loader autodiscover blocks;};
 in {
   inherit (builder) build buildWith;
 }

lib/core/loader.nix

@@ -33,14 +33,18 @@
             }).outputs
           else {};
       in
-        importSignatureFor system updatedCell cells additionalInputs;
+        builtins.addErrorContext "[ren] while getting input signature for ${blockP}" (
+          importSignatureFor system updatedCell cells additionalInputs
+        );
 
       import' = importPath: let
         block = import importPath;
       in
         if l.typeOf block == "set"
         then block
-        else block signature;
+        else
+          builtins.addErrorContext "[ren] while importing block at ${importPath}"
+          (block signature);
 
       importPaths =
         if isFile
@@ -101,7 +105,8 @@
     in
       optionalLoad (isFile || isDir) (
         assert l.assertMsg isAttrs "cell block does not return an attrset: ${importPaths.displayPath}";
-          l.traceVerbose "[ren] loading cell block ${cellBlock.name}, type ${cellBlock.type}, from cell ${cellP}"
+          l.traceVerbose "[ren] loading cell block ${cellBlock.name}, type ${cellBlock.type}, from cell ${cellP}, for system ${system}" (
+            builtins.addErrorContext "[ren] loading cell block ${cellBlock.name}, type ${cellBlock.type}, from cell ${cellP}, for system ${system}"
             [
               {${cellBlock.name} = imported;}
               {${cellBlock.name} = l.mapAttrs (_: set: set.actions) extracted;}
@@ -113,6 +118,7 @@
                 // (l.optionalAttrs (l.pathExists blockP.readmeDir) {readme = blockP.readmeDir;})
                 // (l.optionalAttrs (l.pathExists blockP.readme) {inherit (blockP) readme;}))
             ]
+          )
       );
   in
     loadCellBlock;
@@ -128,12 +134,31 @@
     inherit (utils) unique accumulate;
 
     loadCell = cellName: let
-      cell = res.output;
       cellP = paths.cellPath cellsFrom cellName;
       cellBlocks' = (unique cellBlocks).result;
+      # fixes `ìnfinite recursion` errors when accessing cell attributes from sibling blocks
+      # example: cells/test/a.nix returns `cell.b`, so the same thing as cells/test/b.nix.
+      # this would previously fail with infinite recursion, this makes it work:
+      cell = builtins.addErrorContext "[ren] while accessing cell '${cellName}' siblings" (l.listToAttrs (l.concatMap (
+          block: let
+            blockP = paths.cellBlockPath cellP block;
+            exists = l.pathExists blockP.file || l.pathExists blockP.dir;
+          in
+            if exists
+            then [
+              {
+                name = block.name;
+                # accessing this value will force the loading of this block
+                value = (l.head (loadCellBlock cellName cellP block)).${block.name};
+              }
+            ]
+            else []
+        )
+        cellBlocks'));
       loadCellBlock = createCellBlockLoader {inherit inputs system cells cell transformInputs;};
       res = accumulate (l.map (loadCellBlock cellName cellP) cellBlocks');
-    in [
+    in
+      builtins.addErrorContext "[ren] while loading cell ${cellName}" [
         {${cellName} = res.output;}
         {${cellName} = res.actions;}
         ({

lib/default.nix

@@ -1,9 +1,9 @@
 {lib}: let
   l = builtins // lib;
-  utils = import ./utils {inherit l;};
-  core = import ./core {inherit l utils;};
-  compat = import ./compat {inherit l;};
   blocks = import ./blocks;
+  utils = import ./utils {inherit l;};
+  compat = import ./compat {inherit l;};
+  core = import ./core {inherit l utils blocks;};
 in {
   inherit (compat) filter select get;
   inherit (core) build buildWith;

lib/flake.lock

@@ -2,11 +2,11 @@
   "nodes": {
     "nixpkgs-lib": {
       "locked": {
-        "lastModified": 1754184128,
+        "lastModified": 1766884708,
-        "narHash": "sha256-AjhoyBL4eSyXf01Bmc6DiuaMrJRNdWopmdnMY0Pa/M0=",
+        "narHash": "sha256-x8nyRwtD0HMeYtX60xuIuZJbwwoI7/UKAdCiATnQNz0=",
         "owner": "nix-community",
         "repo": "nixpkgs.lib",
-        "rev": "02e72200e6d56494f4a7c0da8118760736e41b60",
+        "rev": "15177f81ad356040b4460a676838154cbf7f6213",
         "type": "github"
       },
       "original": {

tests/autodiscovery_test.nix

@@ -0,0 +1,63 @@
+{
+  pkgs,
+  ntlib,
+  ...
+}: {
+  suites."Autodiscovery" = {
+    pos = __curPos;
+    tests = [
+      {
+        name = "find nix files";
+        type = "script";
+        script = ''
+          ${ntlib.helpers.path [pkgs.gnugrep pkgs.coreutils pkgs.nix]}
+          ${ntlib.helpers.scriptHelpers}
+
+          mkdir -p "testcell"
+          echo '{ foo = "bar"; }' > "testcell/packages.nix"
+          echo '{ baz = "qux"; }' > "testcell/devShells.nix"
+          echo '{ ignored = true; }' > "testcell/flake.nix"
+
+          result=$(nix eval --impure --expr '
+            let
+              lib = import ${pkgs.path}/lib;
+              autodiscover = import ${../lib/core/autodiscover.nix} {
+                l = builtins // lib;
+                cellsFrom = ./.;
+                cellBlocks = [ { name = "__autodiscover"; } ];
+              };
+            in
+              builtins.length (builtins.filter (b: b.name == "packages" || b.name == "devShells") autodiscover)
+          ')
+
+          assert_eq "$result" "2" "should discover 2 blocks"
+        '';
+      }
+      {
+        name = "finds directories";
+        type = "script";
+        script = ''
+          ${ntlib.helpers.path [pkgs.gnugrep pkgs.coreutils pkgs.nix]}
+          ${ntlib.helpers.scriptHelpers}
+
+          mkdir -p "testcell/packages"
+          echo '{ hello = "world"; }' > "testcell/packages/default.nix"
+
+          result=$(nix eval --impure --expr '
+            let
+              lib = import ${pkgs.path}/lib;
+              autodiscover = import ${../lib/core/autodiscover.nix} {
+                l = builtins // lib;
+                cellsFrom = ./.;
+                cellBlocks = [ { name = "__autodiscover"; } ];
+              };
+            in
+              builtins.any (b: b.name == "packages") autodiscover
+          ')
+
+          assert "$result == true" "Should discover directory with default.nix"
+        '';
+      }
+    ];
+  };
+}

tests/builder_test.nix

@@ -0,0 +1,90 @@
+{
+  pkgs,
+  ntlib,
+  rensa,
+  ...
+}: {
+  suites."Builder" = {
+    pos = __curPos;
+    tests = [
+      {
+        name = "has system outputs";
+        expected = true;
+        actual = let
+          testFlake = rensa.build {
+            inputs = {};
+            cellsFrom = ../cells;
+            cellBlocks = with rensa.blocks; [
+              (simple "test")
+            ];
+            systems = ["x86_64-linux"];
+          };
+        in
+          builtins.hasAttr "x86_64-linux" testFlake;
+      }
+      {
+        name = "has ren metadata";
+        expected = true;
+        actual = let
+          testFlake = rensa.build {
+            inputs = {};
+            cellsFrom = ../cells;
+            cellBlocks = with rensa.blocks; [
+              (simple "test")
+            ];
+            systems = ["x86_64-linux"];
+          };
+        in
+          builtins.hasAttr "__ren" testFlake;
+      }
+      {
+        name = "merges outputs";
+        expected = {
+          packages = {
+            test-package = "merged";
+          };
+        };
+        actual = let
+          testFlake =
+            rensa.buildWith {
+              inputs = {};
+              cellsFrom = ../cells;
+              cellBlocks = with rensa.blocks; [
+                (simple "test")
+              ];
+              systems = ["x86_64-linux"];
+            } {
+              packages = {
+                test-package = "merged";
+              };
+            };
+        in {
+          packages = testFlake.packages;
+        };
+      }
+      {
+        name = "eval test";
+        type = "script";
+        script = ''
+          ${ntlib.helpers.path [pkgs.gnugrep pkgs.coreutils pkgs.nix]}
+          ${ntlib.helpers.scriptHelpers}
+
+          result=$(nix eval --impure --expr '
+            let
+              rensa = import ${../lib} {lib = import ${pkgs.path}/lib;};
+              testFlake = rensa.build {
+                inputs = { test = "value"; };
+                cellsFrom = ${../cells};
+                cellBlocks = [];
+                systems = [ "x86_64-linux" ];
+              };
+            in
+              testFlake.__ren.__schema
+          ')
+
+          assert "$result == \"v0\"" "should contain version"
+        '';
+      }
+    ];
+  };
+}

tests/filter_test.nix

@@ -0,0 +1,51 @@
+{rensa, ...}: {
+  suites."Filter" = {
+    pos = __curPos;
+    tests = [
+      {
+        name = "filter by cell";
+        expected = {
+          x86_64-linux = {};
+        };
+        actual = let
+          testFlake = {
+            __ren = {
+              cells = ["repo" "other"];
+            };
+            x86_64-linux = {
+              repo = {
+                docs = {value = "docs-value";};
+                ci = {value = "ci-value";};
+              };
+              other = {
+                packages = {value = "other-packages";};
+              };
+            };
+          };
+        in
+          rensa.filter (_: cell: cell == "repo") testFlake [["*" "*"]];
+      }
+      {
+        name = "filter by block";
+        expected = {
+          x86_64-linux = {};
+        };
+        actual = let
+          testFlake = {
+            __ren = {
+              cells = ["repo"];
+            };
+            x86_64-linux = {
+              repo = {
+                docs = {value = "docs-value";};
+                ci = {value = "ci-value";};
+                packages = {value = "packages-value";};
+              };
+            };
+          };
+        in
+          rensa.filter (block: _: block == "docs") testFlake [["repo" "*"]];
+      }
+    ];
+  };
+}

tests/loader_test.nix

@@ -0,0 +1,57 @@
+{
+  pkgs,
+  ntlib,
+  rensa,
+  ...
+}: {
+  suites."Loader" = {
+    pos = __curPos;
+    tests = [
+      {
+        name = "cell sibling access";
+        expected = {
+          hello = "world";
+        };
+        actual = let
+          testFlake = rensa.build {
+            inputs = {};
+            cellsFrom = ../cells;
+            cellBlocks = with rensa.blocks; [
+              (simple "test")
+            ];
+            systems = ["x86_64-linux"];
+          };
+        in
+          testFlake.x86_64-linux.test.test;
+      }
+      {
+        name = "load file";
+        type = "script";
+        script = ''
+          ${ntlib.helpers.path [pkgs.gnugrep pkgs.coreutils pkgs.nix]}
+          ${ntlib.helpers.scriptHelpers}
+
+          mkdir -p "cells/testcell"
+          echo '{ hello = "world"; }' > "cells/testcell/packages.nix"
+
+          cat > "flake.nix" << 'EOF'
+          {
+            outputs = inputs: let
+              rensa = import ${../lib} { lib = import "${pkgs.path}/lib"; };
+            in rensa.build {
+              inputs = {};
+              cellsFrom = ./cells;
+              cellBlocks = with rensa.blocks; [ (simple "packages") ];
+              systems = [ "x86_64-linux" ];
+            };
+          }
+          EOF
+
+          result=$(nix eval --impure .#x86_64-linux.testcell.packages.hello)
+
+          assert "$result == \"world\"" "should equal to world"
+        '';
+      }
+    ];
+  };
+}

tests/select_test.nix

@@ -0,0 +1,49 @@
+{rensa, ...}: {
+  suites."Select" = {
+    pos = __curPos;
+    tests = [
+      {
+        name = "single block";
+        expected = {
+          x86_64-linux = {value = "test-value";};
+        };
+        actual = let
+          testFlake = {
+            __ren = {
+              cells = ["repo"];
+            };
+            x86_64-linux = {
+              repo = {
+                docs = {value = "test-value";};
+                ci = {packages = {value = "ci-packages";};};
+              };
+            };
+          };
+        in
+          rensa.select testFlake [["repo" "docs"]];
+      }
+      {
+        name = "multiple blocks";
+        expected = {
+          x86_64-linux = {value = "ci-packages";};
+        };
+        actual = let
+          testFlake = {
+            __ren = {
+              cells = ["repo"];
+            };
+            x86_64-linux = {
+              repo = {
+                ci = {packages = {value = "ci-packages";};};
+                other = {value = "ignored";};
+              };
+            };
+          };
+        in
+          rensa.select testFlake [
+            ["repo" "ci" "packages"]
+          ];
+      }
+    ];
+  };
+}