Add clj-kondo script + build step (athensresearch#38)

* Ignore Emacs and Mac specific files

* Add clj-kondo

Config copied from https://github.com/borkdude/clj-kondo/blob/554d7d93e2eb78ff21cfbbee4a084c4b6e089411/.clj-kondo/config.edn

* Add Lint build step

* Don’t need maven deps for clj-kondo

* Allow clj-kondo warnings for now

* Add TODO for when all warnings are fixed

.clj-kondo/config.edn

@@ -0,0 +1,24 @@
+{:linters {:unused-namespace
+           {:exclude [clj-kondo.impl.rewrite-clj-patch
+                      rewrite-clj.parser.core
+                      clj-kondo.impl.var-info-gen
+                      clj-kondo.impl.node.seq
+                      clj-kondo.impl.profiler]}
+           :unresolved-symbol
+           {:exclude [(clj-kondo.impl.utils/one-of)]}
+           :unused-referred-var
+           {:exclude {clojure.test [is deftest testing]}}
+           :type-mismatch
+           {:level :warning
+            :namespaces
+            {clj-kondo.core {print! {:arities {1 {:args [:map]
+                                                  :ret :nil}}}
+                             run! {:arities {1 {:args [:map]
+                                                :ret :map}}}}
+             clj-kondo.impl.config #include "../src/clj_kondo/impl/config.types.edn"
+             clj-kondo.impl.findings #include "../src/clj_kondo/impl/findings.types.edn"}}
+           :missing-docstring {:level :off}
+           :unsorted-required-namespaces {:level :warning}}
+ :lint-as {me.raynes.conch/programs clojure.core/declare
+           me.raynes.conch/let-programs clojure.core/let}
+ :output {:exclude-files ["src/clj_kondo/impl/rewrite_clj_patch.clj"]}}

.github/workflows/build.yml

@@ -43,3 +43,21 @@ jobs:
       - name: Run tests
         run: |
           script/test/jvm
+          
+  lint:
+    # ubuntu 18.04 comes with lein + java8 installed
+    runs-on: ubuntu-18.04
+    steps:
+      - name: Git checkout
+        uses: actions/checkout@v1
+        with:
+          fetch-depth: 1
+          submodules: 'true'
+
+      - uses: DeLaGuardo/setup-clj-kondo@v1
+        with:
+          version: '2020.04.05'
+
+      - name: Lint 
+        run: |
+          script/lint

.gitignore

@@ -14,3 +14,11 @@
 # shadow-cljs cache, port files
 /.shadow-cljs/
 .idea/
+
+.clj-kondo/.cache
+
+# Mac OS files
+.DS_Store
+
+# Emacs files
+.#*

script/lint

@@ -0,0 +1,9 @@
+#!/usr/bin/env bash
+
+set -eo pipefail
+
+# Find installation instructions here https://github.com/borkdude/clj-kondo/blob/554d7d93e2eb78ff21cfbbee4a084c4b6e089411/doc/install.md
+
+# TODO remove this when all warnings have been fixed
+clj-kondo --lint src || echo "
+[FIXME] fix above warnings and remove this warning"