modules/extraFiles: refactor to use symlinks and support directories

modules/top-level/files/default.nix

@@ -76,28 +76,92 @@ in
       );
 
       # A directory with all the files in it
-      # Implementation based on NixOS's /etc module
-      build.extraFiles = pkgs.runCommandLocal "nvim-config" { passthru.vimPlugin = true; } ''
-        set -euo pipefail
+      # Implementation inspired by NixOS's /etc module
+      build.extraFiles =
+        pkgs.runCommandLocal "nvim-config"
+          {
+            __structuredAttrs = true;
+            targets = lib.catAttrs "target" extraFiles;
+            sources = lib.catAttrs "finalSource" extraFiles;
+            passthru.vimPlugin = true;
+          }
+          ''
+            set -euo pipefail
+
+            numTargets=''${#targets[@]}
+
+            # Check if $1 is a prefix of $2
+            hasPrefix() {
+              case "$2" in
+                "$1"/*) return 0 ;;
+                *) return 1 ;;
+              esac
+            }
+
+            checkPrefix() {
+              if hasPrefix "$1" "$2"; then
+                echo "error: '$1' is a target, but another target conflicts: '$2'" >&2
+                exit 1
+              fi
+            }
+
+            # Fail if two targets conflict (duplicate or file/directory conflict)
+            checkConflict() {
+              local tgtA="$1"
+              local srcA="$2"
+              local tgtB="$3"
+              local srcB="$4"
+
+              # Exact duplicate with different content
+              if
+                [[ "$tgtA" == "$tgtB" ]] && [[ "$srcA" != "$srcB" ]] &&
+                ! diff -q "$srcA" "$srcB" >/dev/null
+              then
+                echo "error: target '$tgtA' defined twice with different sources:" >&2
+                echo "  $srcA" >&2
+                echo "  $srcB" >&2
+                exit 1
+              fi
+
+              # Directory prefix conflicts
+              checkPrefix "$tgtA" "$tgtB"
+              checkPrefix "$tgtB" "$tgtA"
+            }
+
+            # Install symlink to source
+            installTarget() {
+              local tgt="$1"
+              local src="$2"
+              local dest="$out/$tgt"
+              mkdir -p "$(dirname "$dest")"
+              if [[ -e "$dest" ]]; then
+                local existing=$(readlink "$dest" || echo "$dest")
+                if [[ "$existing" != "$src" ]] && ! diff -q "$existing" "$src" >/dev/null; then
+                  echo "error: duplicate target '$tgt' with conflicting content:" >&2
+                  echo "  $existing" >&2
+                  echo "  $src" >&2
+                  exit 1
+                fi
+                return
+              fi
+              ln -s "$src" "$dest"
+            }
 
-        makeEntry() {
-          src="$1"
-          target="$2"
-          mkdir -p "$out/$(dirname "$target")"
-          cp "$src" "$out/$target"
-        }
+            # Validate all targets
+            for ((i=0; i<numTargets; i++)); do
+              for ((j=i+1; j<numTargets; j++)); do
+                checkConflict \
+                  "''${targets[i]}" "''${sources[i]}" \
+                  "''${targets[j]}" "''${sources[j]}"
+              done
+            done
 
-        mkdir -p "$out"
-        ${lib.concatMapStringsSep "\n" (
-          { target, finalSource, ... }:
-          lib.escapeShellArgs [
-            "makeEntry"
-            # Force local source paths to be added to the store
-            "${finalSource}"
-            target
-          ]
-        ) extraFiles}
-      '';
+            # Install all targets
+            mkdir -p "$out"
+            for ((i=0; i<numTargets; i++)); do
+              installTarget "''${targets[i]}" "''${sources[i]}"
+            done
+          '';
 
       # Never combine user files with the rest of the plugins
       performance.combinePlugins.standalonePlugins = [ config.build.extraFiles ];

tests/test-sources/modules/extra-files.nix

@@ -1,15 +1,184 @@
+let
+  checkExtraFiles =
+    pkgs:
+    {
+      name,
+      extraFilesDir,
+      expectedTargets,
+    }:
+    pkgs.runCommand name
+      {
+        inherit extraFilesDir expectedTargets;
+        __structuredAttrs = true;
+      }
+      ''
+        set -euo pipefail
+
+        for target in "''${!expectedTargets[@]}"; do
+          file="$extraFilesDir/$target"
+          expected="''${expectedTargets["$target"]}"
+
+          if [ ! -e "$file" ]; then
+            echo "Missing target: $file"
+            exit 1
+          fi
+
+          if [ -n "$expected" ] && ! grep -qF "$expected" "$file"; then
+            echo "Content mismatch: $file"
+            exit 1
+          fi
+        done
+
+        touch $out
+      '';
+in
 {
+  # Example
   query = {
-    extraFiles = {
-      "testing/test-case.nix".source = ./extra-files.nix;
-      "testing/123.txt".text = ''
-        One
-        Two
-        Three
-      '';
-      "queries/lua/injections.scm".text = ''
-        ;; extends
-      '';
-    };
+    extraFiles."queries/lua/injections.scm".text = ''
+      ;; extends
+    '';
   };
+
+  happy-path =
+    { config, pkgs, ... }:
+    {
+      extraFiles = {
+        # Basic tests
+        "testing/test-case.nix".source = ./extra-files.nix;
+        "testing/123.txt".text = ''
+          One
+          Two
+          Three
+        '';
+
+        # Multiple files in the same directory
+        "foo/a".text = "A";
+        "foo/b".text = "B";
+        "foo/c".text = "C";
+
+        # Nested deep path
+        "a/b/c/d/e.txt".text = "deep";
+
+        # Directory source
+        "beta/dir".source = pkgs.emptyDirectory;
+
+        # Mixed: source file + hello source
+        "hello/source".source = pkgs.hello;
+      };
+      test.runNvim = false;
+      test.extraInputs = [
+        (checkExtraFiles pkgs {
+          name = "check-happy-path";
+          extraFilesDir = config.build.extraFiles;
+          expectedTargets = {
+            "testing/test-case.nix" = null;
+            "testing/123.txt" = "One\nTwo\nThree";
+            "foo/a" = "A";
+            "foo/b" = "B";
+            "foo/c" = "C";
+            "a/b/c/d/e.txt" = "deep";
+            "beta/dir" = null;
+            "hello/source" = null;
+          };
+        })
+      ];
+    };
+
+  # Special content edge cases
+  special-files =
+    { config, pkgs, ... }:
+    {
+      extraFiles = {
+        "empty.txt".text = "";
+        "whitespace.txt".text = "   \n\t  ";
+        "файл.txt".text = "unicode";
+        "目录/文件.txt".text = "chinese";
+      };
+      test.runNvim = false;
+      test.extraInputs = [
+        (checkExtraFiles pkgs {
+          name = "check-special-files";
+          extraFilesDir = config.build.extraFiles;
+          expectedTargets = {
+            "empty.txt" = "";
+            "whitespace.txt" = "   ";
+            "файл.txt" = "unicode";
+            "目录/文件.txt" = "chinese";
+          };
+        })
+      ];
+    };
+
+  duplicate-mismatch =
+    { config, pkgs, ... }:
+    {
+      extraFiles.a = {
+        target = "conflict.txt";
+        text = "abc";
+      };
+      extraFiles.b = {
+        target = "conflict.txt";
+        text = "xyz";
+      };
+      test.buildNixvim = false;
+      test.extraInputs = [
+        (pkgs.runCommand "expect-duplicate-failure"
+          { failure = pkgs.testers.testBuildFailure config.build.extraFiles; }
+          ''
+            exit_code=$(cat "$failure/testBuildFailure.exit")
+            (( exit_code == 1 )) || {
+              echo "Expected exit code 1"
+              exit 1
+            }
+            grep -q "target 'conflict.txt' defined twice with different sources" "$failure/testBuildFailure.log"
+            touch $out
+          ''
+        )
+      ];
+    };
+
+  file-vs-dir-conflict =
+    { config, pkgs, ... }:
+    {
+      extraFiles."conflict".text = "file";
+      extraFiles."conflict/file.txt".text = "nested";
+      test.buildNixvim = false;
+      test.extraInputs = [
+        (pkgs.runCommand "expect-conflict-failure"
+          { failure = pkgs.testers.testBuildFailure config.build.extraFiles; }
+          ''
+            exit_code=$(cat "$failure/testBuildFailure.exit")
+            (( exit_code == 1 )) || {
+              echo "Expected exit code 1"
+              exit 1
+            }
+            grep -q "is a target, but another target conflicts:" "$failure/testBuildFailure.log"
+            touch $out
+          ''
+        )
+      ];
+    };
+
+  dir-vs-file-conflict =
+    { config, pkgs, ... }:
+    {
+      extraFiles."conflictDir".source = pkgs.emptyDirectory;
+      extraFiles."conflictDir/file.txt".text = "nested";
+      test.buildNixvim = false;
+      test.extraInputs = [
+        (pkgs.runCommand "expect-dir-conflict-failure"
+          { failure = pkgs.testers.testBuildFailure config.build.extraFiles; }
+          ''
+            exit_code=$(cat "$failure/testBuildFailure.exit")
+            (( exit_code == 1 )) || {
+              echo "Expected exit code 1"
+              exit 1
+            }
+            grep -q "is a target, but another target conflicts:" "$failure/testBuildFailure.log"
+            touch $out
+          ''
+        )
+      ];
+    };
 }