Clojure via buck in fbcode

.emacs.d/custom.el

@@ -11,6 +11,9 @@
  '(c-indent-level 4)
  '(c-label-minimum-indentation 0)
  '(c-label-offset -4)
+ '(clojure-build-tool-files
+   (quote
+    ("project.clj" "build.boot" "build.gradle" "build.gradle.kts" "deps.edn" "shadow-cljs.edn" "TARGETS")))
  '(comint-input-ignoredups t)
  '(comint-prompt-read-only t)
  '(comint-scroll-to-bottom-on-input t)
@@ -58,7 +61,7 @@
     ((sequence "TODO" "|" "DONE" "ABANDONED" "DEFERRED"))))
  '(package-selected-packages
    (quote
-    (lsp-hack hack-mode rust-mode filladapt vc-hgcmd lsp-ui yaml-mode wgrep fsharp-mode company-lsp cquery mustache-mode clang-format projectile dash-functional mocha add-node-modules-path rjsx-mode xref-js2 js2-refactor company omnisharp geiser cider clojure-mode graphviz-dot-mode multi-term xterm-color thrift markdown-mode tuareg merlin ag use-package flycheck dockerfile-mode js2-mode web-mode zencoding-mode tss switch-window python-mode paredit magit lua-mode go-mode go-autocomplete exec-path-from-shell csharp-mode color-theme-monokai auto-complete auto-complete-nxml flymake flyspell json-mode popup ruby-mode company-jedi tide ahg elm-mode monky)))
+    (xah-lookup lsp-hack hack-mode rust-mode filladapt vc-hgcmd lsp-ui yaml-mode wgrep fsharp-mode company-lsp cquery mustache-mode clang-format projectile dash-functional mocha add-node-modules-path rjsx-mode xref-js2 js2-refactor company omnisharp geiser cider clojure-mode graphviz-dot-mode multi-term xterm-color thrift markdown-mode tuareg merlin ag use-package flycheck dockerfile-mode js2-mode web-mode zencoding-mode tss switch-window python-mode paredit magit lua-mode go-mode go-autocomplete exec-path-from-shell csharp-mode color-theme-monokai auto-complete auto-complete-nxml flymake flyspell json-mode popup ruby-mode company-jedi tide ahg elm-mode monky)))
  '(reb-re-syntax (quote string))
  '(rmail-mail-new-frame t)
  '(safe-local-variable-values

.emacs.d/init.el

@@ -882,5 +882,17 @@
   :config
   (setq rust-format-on-save t))
 
+;; =================================================================
+;; Clojure
+;; =================================================================
+(use-package cider :ensure
+  :config
+  ;; I guess this is a bit wacky, but it's hard to imagine cider without
+  ;; clojure-mode right now.
+  ;;
+  ;; Put TARGETS in clojure-build-tool-files so that directories with TARGETS
+  ;; get identified as projects.
+  (unless (member "TARGETS" clojure-build-tool-files)
+    (setq clojure-build-tool-files (append clojure-build-tool-files '("TARGETS")))))
 
 ;;; init.el ends here

site-lisp/cider-buck.el

@@ -0,0 +1,67 @@
+;;; cider-buck.el --- Cider + Buck = Love            -*- lexical-binding: t; -*-
+
+;; Copyright (C) 2019  John Doty
+
+;; Author: doty <doty@fb.com>
+;; Keywords: languages, clojure, cider
+
+;; This program is free software; you can redistribute it and/or modify
+;; it under the terms of the GNU General Public License as published by
+;; the Free Software Foundation, either version 3 of the License, or
+;; (at your option) any later version.
+
+;; This program is distributed in the hope that it will be useful,
+;; but WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+;; GNU General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with this program.  If not, see <https://www.gnu.org/licenses/>.
+
+;;; Commentary:
+
+;; This is just a bunch of funcitons to make cider work well with a buck
+;; project.
+
+;;; Code:
+
+(defun cider-buck--nrepl-target ()
+  "Get the nrepl buck target of the specified file name."
+  (let ((src-file (buffer-file-name (current-buffer))))
+    (with-temp-buffer
+      (let ((status (call-process "buck" nil (current-buffer) nil
+                                  "query" "owner('%s')" src-file)))
+        (unless (eq status 0)
+          (error (buffer-string)))
+
+        (goto-char (point-min))
+        (while (re-search-forward "__source-java[0-9]+$" nil t)
+          (replace-match "_nrepl"))
+
+        (goto-char (point-min))
+        (buffer-substring (point-min) (line-end-position))))))
+
+(defun cider-buck--jack-in-cmd ()
+  "Get it."
+  (concat "buck run " (cider-buck--nrepl-target) " -- --middleware '["
+          (mapconcat (apply-partially #'format "\"%s\"")
+                     (cider-jack-in-normalized-nrepl-middlewares)
+                     ", ")
+          "]'"))
+
+(defun cider-buck--project-dir ()
+  "Get the project dir by looking for a targets file."
+  (locate-dominating-file (buffer-file-name (current-buffer)) "TARGETS"))
+
+(defun cider-buck-jack-in ()
+  "Start an nREPL server for the current file and connect to it."
+  (interactive)
+  (nrepl-start-server-process
+   (cider-buck--project-dir)
+   (cider-buck--jack-in-cmd)
+   (lambda (server-buffer)
+     (cider-connect-sibling-clj () server-buffer))))
+
+
+(provide 'cider-buck)
+;;; cider-buck.el ends here