fzf: warn on conflicting ctrl-r bindings

Detect active fzf and history-manager Ctrl-R bindings by their configured values, warn with the winning precedence, and let the normal binding options silence the warning.

tests/modules/programs/atuin/nushell-fzf-order.nix

@@ -22,6 +22,7 @@
     fzf = {
       enable = true;
       enableNushellIntegration = true;
+      historyWidget.nushell.command = "";
 
       package = config.lib.test.mkStubPackage {
         name = "fzf";
@@ -51,6 +52,7 @@
     ''
       assertFileExists "${nushellConfigFile}"
       assertFileContent "$(normalizeStorePaths "${nushellConfigFile}")" ${builtins.toFile "nushell-fzf-atuin-order-expected.nu" ''
+        $env.FZF_CTRL_R_COMMAND = ""
         source /nix/store/00000000000000000000000000000000-nushell-fzf-integration.nu
 
         source /nix/store/00000000000000000000000000000000-atuin-nushell-config.nu

tests/modules/programs/fzf/ctrl-r-conflict-atuin-disabled.nix

@@ -0,0 +1,27 @@
+{ config, ... }:
+
+{
+  programs = {
+    atuin = {
+      enable = true;
+      enableZshIntegration = true;
+      flags = [ "--disable-ctrl-r" ];
+      package = config.lib.test.mkStubPackage { name = "atuin"; };
+    };
+
+    fzf = {
+      enable = true;
+      enableZshIntegration = true;
+      package = config.lib.test.mkStubPackage {
+        name = "fzf";
+        version = "0.73.0";
+      };
+    };
+
+    zsh.enable = true;
+  };
+
+  nmt.script = ''
+    assertFileExists home-files/.zshrc
+  '';
+}

tests/modules/programs/fzf/ctrl-r-conflict-fzf-disabled.nix

@@ -0,0 +1,27 @@
+{ config, ... }:
+
+{
+  programs = {
+    atuin = {
+      enable = true;
+      enableZshIntegration = true;
+      package = config.lib.test.mkStubPackage { name = "atuin"; };
+    };
+
+    fzf = {
+      enable = true;
+      enableZshIntegration = true;
+      historyWidget.command = "";
+      package = config.lib.test.mkStubPackage {
+        name = "fzf";
+        version = "0.73.0";
+      };
+    };
+
+    zsh.enable = true;
+  };
+
+  nmt.script = ''
+    assertFileExists home-files/.zshrc
+  '';
+}

tests/modules/programs/fzf/ctrl-r-conflict-per-shell-disabled.nix

@@ -0,0 +1,27 @@
+{ config, ... }:
+
+{
+  programs = {
+    atuin = {
+      enable = true;
+      enableZshIntegration = true;
+      package = config.lib.test.mkStubPackage { name = "atuin"; };
+    };
+
+    fzf = {
+      enable = true;
+      enableZshIntegration = true;
+      historyWidget.zsh.command = "";
+      package = config.lib.test.mkStubPackage {
+        name = "fzf";
+        version = "0.73.0";
+      };
+    };
+
+    zsh.enable = true;
+  };
+
+  nmt.script = ''
+    assertFileExists home-files/.zshrc
+  '';
+}

tests/modules/programs/fzf/ctrl-r-conflict-warning.nix

@@ -0,0 +1,55 @@
+{
+  config,
+  lib,
+  options,
+  ...
+}:
+
+{
+  programs = {
+    atuin = {
+      enable = true;
+      enableZshIntegration = true;
+      package = config.lib.test.mkStubPackage { name = "atuin"; };
+    };
+
+    fzf = {
+      enable = true;
+      enableZshIntegration = true;
+      package = config.lib.test.mkStubPackage {
+        name = "fzf";
+        version = "0.73.0";
+      };
+    };
+
+    zsh.enable = true;
+  };
+
+  test.asserts.warnings.expected = [
+    ''
+      programs.fzf and a history manager both configure Ctrl-R for zsh.
+
+      Definitions:
+        zsh:
+          `programs.fzf.enable` defined in ${lib.showFiles options.programs.fzf.enable.files}
+          `programs.atuin.enable` defined in ${lib.showFiles options.programs.atuin.enable.files}
+
+      The history manager integration is sourced after fzf and owns Ctrl-R.
+      Choose which integration should own Ctrl-R.
+      To keep the history manager on Ctrl-R, disable fzf's binding:
+        programs.fzf.historyWidget.command = "";
+      or disable it for one shell:
+        programs.fzf.historyWidget.zsh.command = "";
+      To keep fzf on Ctrl-R with Atuin, disable Atuin's Ctrl-R binding:
+        programs.atuin.flags = [ "--disable-ctrl-r" ];
+      McFly has no Ctrl-R-only option in Home Manager. Disable McFly's
+      shell integration for that shell if fzf should own Ctrl-R.
+      To use another key, disable one default Ctrl-R binding and add a
+      shell-specific key binding in your shell configuration.
+    ''
+  ];
+
+  nmt.script = ''
+    assertFileExists home-files/.zshrc
+  '';
+}

tests/modules/programs/fzf/default.nix

@@ -1,5 +1,9 @@
 {
   fzf-bash-widget-overrides = ./bash-widget-overrides.nix;
+  fzf-ctrl-r-conflict-atuin-disabled = ./ctrl-r-conflict-atuin-disabled.nix;
+  fzf-ctrl-r-conflict-fzf-disabled = ./ctrl-r-conflict-fzf-disabled.nix;
+  fzf-ctrl-r-conflict-per-shell-disabled = ./ctrl-r-conflict-per-shell-disabled.nix;
+  fzf-ctrl-r-conflict-warning = ./ctrl-r-conflict-warning.nix;
   fzf-disabled = ./disabled.nix;
   fzf-options = ./all-options.nix;
   fzf-bash-integration = ./bash-integration.nix;