fix issue with duplicate errors

fixes #75

src/fennel-ls/completion.fnl

@@ -137,9 +137,12 @@ we support completionItem/resolve."
 
     (fn binding-completions []
       "completions when you're writing a destructure pattern. We suggest identifiers which are unknown"
-      (each [_ {: message} (ipairs file.compile-errors)]
-        (case (message:match "unknown identifier: ([a-zA-Z0-9_-]+)")
-          identifier (add-completion! identifier {} :Variable))))
+      (let [seen {}]
+        (each [_ {: message} (ipairs file.compile-errors)]
+          (case (message:match "unknown identifier: ([a-zA-Z0-9_-]+)")
+            (where identifier (not (. seen identifier)))
+            (do (tset seen identifier true)
+                (add-completion! identifier {} :Variable))))))
 
     (when symbol
       (if (. file.definitions symbol)

test/completion.fnl

@@ -116,6 +116,13 @@
                           (+ number-of-x 1)
                           number-of-x))))
          [])
+  (check "(let [f| 10] foo foo foo"
+         (fn [completions]
+           (faith.= 1 (accumulate [number-of-foo 0 _ completion (ipairs completions.items)]
+                        (if (= completion.label :foo)
+                          (+ number-of-foo 1)
+                          number-of-foo))))
+         [])
   ;; completions of fields (nested)
   (check "(local x {:y {:z {:a {:b 1}}}}) ; deep tables
           (local m {}) ; split modules

test/lint.fnl

@@ -381,6 +381,22 @@
   (assert-ok "(and true (or false true))") ; different operators
   nil)
 
+(fn test-zero-indexed []
+  (let [add-opts #{:main.fnl $ :flsproject.fnl "{:lints {:zero-indexed true}}"}]
+    (check (add-opts "(local x {})
+                      (. x 0)")
+           [{:code "zero-indexed"
+             :message "indexing a table with 0; did you forget that Lua is 1-indexed?"}])
+    (check (add-opts "(. math 0)")
+           [{:code "zero-indexed"
+             :message "indexing a table with 0; did you forget that Lua is 1-indexed?"}])
+    (assert-ok (add-opts "(. math 1)"))
+    (assert-ok (add-opts "(. arg 0)"))
+    (assert-ok (add-opts "(. math :0)")))
+  nil)
+
+
+
 {: test-unused
  : test-ampersand
  : test-unknown-module-field
@@ -397,4 +413,5 @@
  : test-decreasing-comparison
  : test-arg-count
  : test-duplicate-keys
- : test-nested-associative-operator}
+ : test-nested-associative-operator
+ : test-zero-indexed}