Fix various false positives for clojure.test (#373)

Close #116 (nothing had to be fixed; only proves that the bug is now absent)
Fixes #207
Fixes #313

cases/testcases/clojure_test.clj

@@ -0,0 +1,26 @@
+(ns testcases.clojure-test
+  (:require
+   [clojure.test :refer [are assert-expr deftest do-report is join-fixtures testing use-fixtures]]))
+
+(defmethod assert-expr 'truthy?
+  [msg [pred v]]
+  `(do-report (if ~v
+                {:type :pass, :message ~msg}
+                {:type :fail, :message ~msg})))
+
+(defn throws-exception []
+  (throw (ex-info "" {})))
+
+(defn func [f] "")
+
+;; https://github.com/jonase/eastwood/issues/116
+(deftest exercises-thrown
+  (is (thrown? Exception (throws-exception))))
+
+;; https://github.com/jonase/eastwood/issues/313
+(deftest exercises-truthy
+  (is (truthy? 42)))
+
+;; https://github.com/jonase/eastwood/issues/207
+(deftest b-test
+  (is (instance? String (func +))))

changes.md

@@ -11,6 +11,10 @@
 
 #### Bugfixes
 
+* Fix false positive `suspicious-expression` for `clojure.test/is`
+  * Fixes https://github.com/jonase/eastwood/issues/207
+* Support `clojure.test/assert-expr` better
+  * Fixes https://github.com/jonase/eastwood/issues/313
 * Vanilla `defn`s having `:test` metadata don't result in false positives for the `:bad-arglists` linter anymore. 
 
 ## Changes from 0.3.14 to 0.4.0 

resource/eastwood/config/clojure.clj

@@ -51,6 +51,12 @@
   :within-depth 8
   :reason "clojure.spec's `coll-of` can contain `clojure.core/or` invocations with only one argument."})
 
+(disable-warning
+ {:linter :constant-test
+  :if-inside-macroexpansion-of #{'clojure.test/is}
+  :within-depth 2
+  :reason "`is` can contain arbitrary exprs that are \"constant-looking\". They typically intend to exercise a predicate."})
+
 (disable-warning
  {:linter :constant-test
   :if-inside-macroexpansion-of #{'clojure.core/cond-> 'clojure.core/cond->>}

src/eastwood/linters/typos.clj

@@ -692,7 +692,7 @@
                                     :init  ; in :op :binding
                                     :args  ; in :op :invoke for clojure.core/list
                                     )
-                num-args (count fn-args-ast-vec)
+                num-args (some-> fn-args-ast-vec count)
                 fn-var (-> let-bindings-ast
                            second  ; in vector of 2 bindings
                            :init   ; in :op :binding
@@ -726,7 +726,8 @@
 ;;                    (println (format "    loc=%s" loc))
 ;;                    )
                 ]
-          :when (contains? suspicious-args num-args)]
+          :when (and num-args
+                     (contains? suspicious-args num-args))]
       {:loc loc
        :linter :suspicious-expression
        :msg (format "%s called with %d args.  (%s%s) always returns %s.  Perhaps there are misplaced parentheses?"

test/eastwood/lint_test.clj

@@ -203,3 +203,8 @@ relative to a specific macroexpansion"
 
     "only `true` is deemed an apt :qualifier value"
     #{'testcases.are-true.red-three} {:some-warnings true}))
+
+(deftest clojure-test-test
+  (testing "Some reported false positives against clojure.test"
+    (is (= {:some-warnings false}
+           (eastwood.lint/eastwood (assoc eastwood.lint/default-opts :namespaces #{'testcases.clojure-test}))))))