fix push diagnostics sending outdated diagnostics

src/fennel-ls/handlers.fnl

@@ -234,9 +234,9 @@ Every time the client sends a message, it gets handled by a function in the corr
     (send (message.diagnostics file))))
 
 (λ notifications.textDocument/didChange [server send {: contentChanges :textDocument {: uri}}]
-  (local file (files.get-by-uri server uri))
-  (files.set-uri-contents server uri (utils.apply-changes file.text contentChanges server.position-encoding))
-  (push-diagnostics server file send))
+  (let [file (files.get-by-uri server uri)
+        file (files.set-uri-contents server uri (utils.apply-changes file.text contentChanges server.position-encoding))]
+    (push-diagnostics server file send)))
 
 (λ notifications.textDocument/didOpen [server send {:textDocument {: text : uri}}]
   (local file (files.set-uri-contents server uri text))

test/diagnostic.fnl

@@ -192,10 +192,28 @@
          [{:message "expected whitespace before token"}]
          []))
 
+(fn test-after-edit []
+  (let [{: uri : client : locations}
+        (create-client "(fn abc [] (+ a====))
+                        {: abc}"
+                       ;; wants push notifications
+                       {:capabilities {:textDocument {:publishDiagnostics true}}})
+        [{:params {: diagnostics}}] (client:change-text! uri [{:range (. locations 1 :range) :text " b"}])]
+    (faith.= diagnostics [{:code "compiler-error"
+                           :message "unknown identifier: a"
+                           :range {:end {:character 15 :line 0} :start {:character 14 :line 0}}
+                           :severity 1}
+                          {:code "compiler-error"
+                           :message "unknown identifier: b"
+                           :range {:end {:character 17 :line 0} :start {:character 16 :line 0}}
+                           :severity 1}])
+    nil))
+
 {: test-lua-versions
  : test-macro-environment
  : test-compile-error
  : test-parse-error
  : test-macro-error
  : test-multiple-errors
- : test-warnings}
+ : test-warnings
+ : test-after-edit}

test/utils/client.fnl

@@ -24,6 +24,15 @@
 (fn pretend-this-file-exists! [self name text]
   (tset self.server.preload name text))
 
+(fn change-text! [self name contentChanges]
+  (dispatch.handle* self.server
+    (message.create-notification :textDocument/didChange
+      {: contentChanges
+       :textDocument
+       {:uri name
+        :languageId "fennel"
+        :version 2}})))
+
 (fn completion [self file position]
   (dispatch.handle* self.server
     (message.create-request (next-id! self) :textDocument/completion
@@ -103,6 +112,7 @@
 
 (local client-mt
   {:__index {: open-file!
+             : change-text!
              : pretend-this-file-exists!
              : completion
              : completion-item-resolve