From ae66e6d002a35ff69e9519e3f5b64fe8e2f57476 Mon Sep 17 00:00:00 2001
From: XeroOl <xerool@protonmail.com>
Date: Sun, 19 Jan 2025 19:56:37 -0600
Subject: [PATCH] analyzer can search into macro expansions and functions

shoutouts to rudy for working with me on these changes.
---
 src/fennel-ls/analyzer.fnl | 15 ++++++++++++---
 src/fennel-ls/compiler.fnl |  9 ++++++---
 test/goto-definition.fnl   | 30 +++++++++++++++++++++++++++---
 3 files changed, 45 insertions(+), 9 deletions(-)

diff --git a/src/fennel-ls/analyzer.fnl b/src/fennel-ls/analyzer.fnl
index 10c2cf6..a1b3eab 100644
--- a/src/fennel-ls/analyzer.fnl
+++ b/src/fennel-ls/analyzer.fnl
@@ -42,6 +42,7 @@ find the definition `10`, but if `opts.stop-early?` is set, it would find
 (local utils (require :fennel-ls.utils))
 (local files (require :fennel-ls.files))
 (local docs (require :fennel-ls.docs))
+(local {: view} (require :fennel))
 
 (local get-ast-info utils.get-ast-info)
 
@@ -146,11 +147,19 @@ find the definition `10`, but if `opts.stop-early?` is set, it would find
         (where (or :fn :lambda :λ))
         (if (and (= multival 1) (= 0 (length stack)))
           {:definition call : file}) ;; BASE CASE !!
-        ;; TODO expand-macros
 
         _
-        (if (and (= multival 1) (= 0 (length stack)))
-          {:definition call : file}))))) ;; BASE CASE!!
+        (case (. file.macro-calls call)
+          macroexpanded (search-multival server file macroexpanded stack multival opts)
+          _ (case (search-val server file (. call 1) [] {})
+              (where {: definition : file}
+                     (list? definition)
+                     (let [head (. definition 1)]
+                       (or (sym? head :fn)
+                           (sym? head :lambda)
+                           (sym? head :λ))))
+
+              (search-multival server file (. definition (length definition)) stack multival opts)))))))
 
 (set search-multival
   (λ [server file ?ast stack multival opts]
diff --git a/src/fennel-ls/compiler.fnl b/src/fennel-ls/compiler.fnl
index ec5afc1..4f8d43c 100644
--- a/src/fennel-ls/compiler.fnl
+++ b/src/fennel-ls/compiler.fnl
@@ -67,7 +67,8 @@ identifiers are declared / referenced in which places."
         scopes        {} ; ast -> scope
         calls         {} ; all calls in the macro-expanded code -> true
         lexical       {} ; all lists, tables, and symbols in the original source
-        require-calls {}] ; the keys are all the calls that start with `require
+        require-calls {} ; the keys are all the calls that start with `require
+        macro-calls   {}]; ast -> expanded
 
     (local defer [])
 
@@ -235,8 +236,9 @@ identifiers are declared / referenced in which places."
           (let [len (length ast)]
             (table.insert defer #(tset ast (+ len 1) nil))))))
 
-    (fn macroexpand [ast _transformed scope]
+    (fn macroexpand [ast transformed scope]
       "every list that is a call to a macro"
+      (tset macro-calls ast transformed)
       (let [macro-id (. ast 1)
             macro-fn (accumulate [t scope.macros
                                   _ part (ipairs (utils.multi-sym-split macro-id))]
@@ -423,6 +425,7 @@ identifiers are declared / referenced in which places."
       (set file.references references)
       (set file.require-calls require-calls)
       (set file.allowed-globals allowed-globals)
-      (set file.macro-refs macro-refs))))
+      (set file.macro-refs macro-refs)
+      (set file.macro-calls macro-calls))))
 
 {: compile}
diff --git a/test/goto-definition.fnl b/test/goto-definition.fnl
index d6c1ae9..8e040cb 100644
--- a/test/goto-definition.fnl
+++ b/test/goto-definition.fnl
@@ -205,22 +205,46 @@
   (check "|#$...")
   nil)
 
+(fn test-thru-function-return []
+  (check {:button.fnl "(fn new []
+                          {:options =={}==})
+                       {: new}"
+          :main.fnl "(let [button (require :button)
+                           b (button.new)]
+                       b.options|"})
+  (check "(fn foo [] (values {} =={}== {}))
+          (local (x y| z) (foo))")
+  (check "(fn foo [] [{} =={}== {}])
+          (local [x y| z] (foo))")
+  nil)
+(fn test-macro []
+  "Macros are mostly unsupported for now.
+  Fennel-ls can understand the expansion of macros, because it mostly operates
+  on the post-expansion version of the AST."
+  ;; Can see the expansion of a macro
+  (check "(macro hello [x y z] y)
+          (local x| (hello {} =={}== {}))")
+  ;; ;; Can see the macro itself
+  ;; (check "==(macro hello [x y z] y)==
+  ;;         (local x (hello| {} {} {})")
+
+  nil)
+
 ; ;; (it "can go to a destructured function argument")
-; ;; (it "can go through more than one file")
 ; ;; (it "will give up instead of freezing on recursive requires")
 ; ;; (it "will give up instead of freezing on recursive tables constructed with (set)")
-; ;; (it "finds the definition of in-file macros")
 ; ;; (it "can follow import-macros (destructuring)")
 ; ;; (it "can follow import-macros (namespaced)")
 ; ;; (it "can go to the definition in a lua file")
 ; ;; (it "finds (set a.b) definitions")
 ; ;; (it "finds (tset a :b) definitions")
 ; ;; (it "finds (setmetatable a {:__index {:b def}) definitions")
-; ;; (it "finds definitions into a function (fn foo [] (local x 10) {: x}) (let [result (foo)] (print result.x)) finds result.x")
 ; ;; (it "finds definitions through a function (fn foo [{: y}] {:x y}) (let [result (foo {:y {}})] (print result.x)) finds result.x")
 ; ;; (it "finds through setmetatable with an :__index function")
 
 {: test-local
  : test-fields
  : test-thru-require
+ : test-thru-function-return
+ : test-macro
  : test-no-crash}