fennel-ls/test/lint.fnl
2025-01-05 12:39:10 -08:00

271 lines
9.5 KiB
Fennel

(local faith (require :faith))
(local {: view} (require :fennel))
(local {: create-client} (require :test.utils))
(fn find [diagnostics e]
"returns the index of the diagnostic "
(accumulate [result nil
i d (ipairs diagnostics)
&until result]
(if (and (or (= e.message nil)
(if (= (type e.message) "function")
(e.message d.message)
(= e.message d.message)))
(or (= e.code nil)
(= e.code d.code))
(or (= e.range nil)
(and (= e.range.start.line d.range.start.line)
(= e.range.start.character d.range.start.character)
(= e.range.end.line d.range.end.line)
(= e.range.end.character d.range.end.character))))
i)))
(fn check [file-contents expected ?unexpected]
(let [{: diagnostics} (create-client file-contents)]
(each [_ e (ipairs (or ?unexpected []))]
(let [i (find diagnostics e)]
(faith.= nil i (.. "Lint matching " (view e) "\n"
"from: " (view file-contents) "\n"
(view (. diagnostics i) {:escape-newlines? true})))))
(each [_ e (ipairs expected)]
(let [i (find diagnostics e)]
(faith.is i (.. "No lint matching " (view e) "\n"
"from: " (view file-contents) "\n"
(view diagnostics {:empty-as-sequence? true
:escape-newlines? true})))
(table.remove diagnostics i)))))
(fn assert-ok [file-contents]
(let [{: diagnostics} (create-client file-contents)]
(faith.= nil (next diagnostics) (view diagnostics))))
(fn test-unused []
(check "(local x 10)"
[{:message "unused definition: x"
:code 301
:range {:start {:character 7 :line 0}
:end {:character 8 :line 0}}}])
(check "(fn x [])"
[{:message "unused definition: x"
:code 301
:range {:start {:character 4 :line 0}
:end {:character 5 :line 0}}}])
(check "(let [(x y) (values 1 2)] x)"
[{:code 301
:range {:start {:character 9 :line 0}
:end {:character 10 :line 0}}}])
;; setting a var without reading
(check "(var x 1) (set x 2) (set [x] [3])"
[{:code 301
:range {:start {:character 5 :line 0}
:end {:character 6 :line 0}}}])
;; setting a field without reading is okay
(assert-ok "(fn [a b] (set a.x 10) (fn b.f []))")
(assert-ok "(case {:b 1} (where (or {:a x} {:b x})) x)")
(check "(fn foo [a] nil) (foo)" [{:message "unused definition: a"}])
(check "(λ foo [a] nil) (foo)" [{:message "unused definition: a"}])
(check "(lambda foo [a] nil) (foo)" [{:message "unused definition: a"}])
nil)
(fn test-ampersand []
(assert-ok "(let [[x & y] [1 2 3]]
(print x (. y 1) (. y 2)))")
(assert-ok "(let [{1 x & y} [1 2 3]]
(print x (. y 2) (. y 3)))")
(assert-ok "(let [[x &as y] [1 2 3]]
(print x (. y 2) (. y 3)))")
(assert-ok "(let [{1 x &as y} [1 2 3]]
(print x (. y 2) (. y 3)))")
(assert-ok "(fn [x & more]
(print x more))")
nil)
(fn test-unknown-module-field []
(check {:the-guy-they-tell-you-not-to-worry-about.fnl
"(local M {:a 1})
(fn M.b [] 2)
M"
:main.fnl
"(local {: a : c &as guy} (require :the-guy-they-tell-you-not-to-worry-about))
(print guy.b guy.d)"}
[{:code 302 :message "unknown field: c"}
{:code 302 :message "unknown field: guy.d"}]
[{:code 302 :message "unknown field: a"}
{:code 302 :message "unknown field: b"}])
(check "table.insert2 table.insert"
[{:code 302 :message "unknown field: table.insert2"}]
[{:code 302 :message "unknown field: table.insert"}])
;; if you explicitly write "_G", it should turn off this test.
;; Hardcoded at the top of analyzer.fnl/search-document.
(check "_G.insert2"
[]
[{:code 302}])
;; we don't care about nested
(check {:requireme.fnl "{:field []}"
:main.fnl "(local {: field} (require :requireme))
field.unknown"}
[]
[{:code 302}])
(check "package.loaded.mymodule io.stderr.write"
[]
[{:code 302}])
nil)
(fn test-unnecessary-colon []
(check "(let [x :haha] (: x :find :a))"
[{:message "unnecessary : call: use (x:find)"
:code 303
:range {:start {:character 15 :line 0}
:end {:character 29 :line 0}}}])
;; no warning from macros
(assert-ok "(let [x :haha y :find] (-> x (: y :a))
(let [x :haha] (-> x (: :find :a))))")
;; no warning when its an expression, or when string has spaces
(assert-ok "(let [x :haha]
(: x \"bar baz\") (: x 1) (: x x))")
nil)
(fn test-unpack-into-op []
(check "(+ (unpack [1 2 3]))"
[{:code 304}])
(check "(.. (table.unpack [\"hello\" \"world\"]))"
[{:code 304 :message #($:find "table.concat")}])
(check "(* (table.unpack [\"hello\" \"world\"]))"
[{:code 304 :message #(not ($:find "table%.concat"))}])
;; only when lexical
(assert-ok "(-> [1 2 3] table.unpack +)")
nil)
(fn test-unset-var []
(check "(var x nil) (print x)"
[{:code 305
:range {:start {:character 5 :line 0}
:end {:character 6 :line 0}}}])
(assert-ok "(var x 1) (set x 2) (print x)")
(assert-ok "(local x 10) (?. x)")
nil)
;; missing test for 306
(fn test-unpack-in-middle []
(check "(+ 1 2 3 (values 4 5) 6)"
[{:code 307
:range {:start {:line 0 :character 9}
:end {:line 0 :character 21}}}])
;; not in a statement, should be covered by another lint
(assert-ok "(let [x 10] (values 4 5) x)")
(assert-ok "(do (values 4 5) (_G.unpack 6 7) (table.unpack 8 9) 10)")
nil)
(fn test-unnecessary-tset []
;; valid, if you're targeting older Fennels
(assert-ok "(local [tbl key] [{} :k]) (tset tbl key 249)")
;; never a good use of tset
(check "(local tbl {}) (tset tbl :key 9)"
[{:code 309
:codeDescription "unnecessary-tset"
:message "unnecessary tset"
:range {:start {:character 15 :line 0}
:end {:character 32 :line 0}}}])
;; Lint only triggers on keys that can be written as a sym
(check "(local tbl {}) (tset tbl \"hello-world\" 249)" [{:code 309}])
(assert-ok "(local tbl {}) (tset tbl \"01234567\" 249)")
(assert-ok "(local tbl {}) (tset tbl \"hello world\" 1)")
(assert-ok "(local tbl {}) (tset tbl \"0123.4567\" 1)")
nil)
(fn test-unnecessary-do []
;; multi-arg do
(assert-ok "(do (print :x) 11)")
;; unnecessary do
(check "(do 9)" [{:message "unnecessary do"
:code 310
:codeDescription "unnecessary-do-values"
:range {:start {:character 0 :line 0}
:end {:character 6 :line 0}}}])
;; unnecessary values
(check "(print :hey (values :lol))"
[{:code 310
:codeDescription "unnecessary-do-values"
:message "unnecessary values"
:range {:start {:character 12 :line 0}
:end {:character 25 :line 0}}}])
nil)
(fn test-redundant-do []
;; good do
(assert-ok "(case 134 x (do (print :x x) 11))")
;; unnecessary one
(check "(let [x 29] (do (print 9) x))"
[{:code 311
:codeDescription "redundant-do"
:message "redundant do"
:range {:start {:character 12 :line 0}
:end {:character 28 :line 0}}}])
nil)
(fn test-match-should-case []
;; most basic pinning
(assert-ok "(let [x 99] (match 99 x :yep!))")
;; pinning inside where clause
(assert-ok "(let [x 99]
(match 98
y (print y)
(where x (= 0 (math.fmod x 2))) (print x)))")
;; nested pinning
(assert-ok "(let [x 99]
(match [{:x 32}]
[{: x}] (print x)))" [] [{}])
;; values pattern
(assert-ok "(let [x 99]
(match 49
(x _ 9) (print :values-ref)))")
;; warn: basic no pinning
(check "(match 91 z (print :yeah2 z))"
[{:message "no pinned patterns; use case instead of match"
:code 308
:range {:start {:character 1 :line 0}
:end {:character 6 :line 0}}}])
;; warn: nested no pinning
(check "(match [32] [lol] (print :nested-no-pin lol))"
[{:message "no pinned patterns; use case instead of match"
:code 308
:range {:start {:character 1 :line 0}
:end {:character 6 :line 0}}}])
nil)
;; TODO lints:
;; duplicate keys in kv table
;; (tset <sym> <any>) --> (set (. <sym> <any>)) (might be wanted for compat?)
;; {&as x} and [&as x] pattern with no other matches
;; Unused variables / fields (maybe difficult)
;; discarding results to various calls, such as unpack, values, etc
;; `pairs` or `ipairs` call in a (for) binding table
;; steal as many lints as possible from cargo
;; unnecessary parens around single multival destructure
;; unused variable, when a function binding is only used in its body, and the function value is discarded
{: test-unused
: test-ampersand
: test-unknown-module-field
: test-unnecessary-colon
: test-unnecessary-tset
: test-unnecessary-do
: test-redundant-do
: test-unset-var
: test-match-should-case
: test-unpack-into-op
: test-unpack-in-middle
}