feat: add m_end position to AST nodes

- Add end line and column (m_end.m_line, m_end.m_col) to AST output
- New AST format: [name, begin_line, begin_col, end_line, end_col, ...children]
- Update format_spec.yue to normalize end positions for comparison
- Add ast_spec.yue tests for AST end position feature

Closes #251

2 files changed, 94 insertions, 1 deletions

diff --git a/spec/inputs/test/ast_spec.yue b/spec/inputs/test/ast_spec.yue
new file mode 100644
index 0000000..11efc94
--- /dev/null
+++ b/spec/inputs/test/ast_spec.yue
@@ -0,0 +1,91 @@
+yue = require "yue"
+
+describe "yue.to_ast", ->
+        it "should return AST with end position for simple expression", ->
+                ast = yue.to_ast "x = 1"
+                assert.is_not_nil ast
+                -- ast format: [name, begin_line, begin_col, end_line, end_col, ...children]
+                assert.same ast[1], "File"
+                assert.same ast[2], 1  -- begin line
+                assert.same ast[3], 1  -- begin col
+                assert.is_number ast[4]  -- end line
+                assert.is_number ast[5]  -- end col
+
+        it "should have correct end position for leaf nodes", ->
+                ast = yue.to_ast "1"
+                assert.is_not_nil ast
+                -- Leaf node with no children should have format: [name, begin_line, begin_col, end_line, end_col, value]
+                assert.same ast[1], "File"
+                assert.same ast[2], 1
+                assert.same ast[3], 1
+                assert.is_number ast[4]
+                assert.is_number ast[5]
+
+        it "should have end position for multi-line code", ->
+                code = [[
+x = 1
+y = 2]]
+                ast = yue.to_ast code
+                assert.is_not_nil ast
+                assert.same ast[1], "File"
+                assert.same ast[2], 1
+                assert.same ast[3], 1
+                -- End position should be on line 2
+                assert.is_true ast[4] >= 2
+
+        it "should have end position for function definition", ->
+                code = [[
+add = (a, b) ->
+        a + b]]
+                ast = yue.to_ast code
+                assert.is_not_nil ast
+                assert.same ast[1], "File"
+                assert.same ast[2], 1
+                assert.same ast[3], 1
+                assert.is_number ast[4]
+                assert.is_number ast[5]
+
+        it "should have end position for table literal", ->
+                ast = yue.to_ast "{a: 1, b: 2}"
+                assert.is_not_nil ast
+                assert.same ast[1], "File"
+                assert.same ast[2], 1
+                assert.same ast[3], 1
+                assert.is_number ast[4]
+                assert.is_number ast[5]
+
+        it "should have end position for class definition", ->
+                code = [[
+class Person
+        new: (@name) =>
+        getName: => @name]]
+                ast = yue.to_ast code
+                assert.is_not_nil ast
+                assert.same ast[1], "File"
+                assert.same ast[2], 1
+                assert.same ast[3], 1
+                assert.is_true ast[4] >= 3
+
+        it "should return nil and error message for invalid syntax", ->
+                ast, err = yue.to_ast "if then else"
+                assert.is_nil ast
+                assert.is_string err
+
+        it "should support flatten level parameter", ->
+                ast = yue.to_ast "x = 1", 0
+                assert.is_not_nil ast
+                assert.same ast[1], "File"
+                assert.is_number ast[4]
+                assert.is_number ast[5]
+
+        it "should have end position in nested structures", ->
+                code = "x = [i for i = 1, 10]"
+                ast = yue.to_ast code
+                assert.is_not_nil ast
+                assert.same ast[1], "File"
+                assert.same ast[2], 1
+                assert.same ast[3], 1
+                assert.is_number ast[4]
+                assert.is_number ast[5]
+                -- End column should reflect the end of the expression
+                assert.is_true ast[5] > 1
diff --git a/spec/inputs/test/format_spec.yue b/spec/inputs/test/format_spec.yue
index 8c6096a..310b610 100644
--- a/spec/inputs/test/format_spec.yue
+++ b/spec/inputs/test/format_spec.yue
@@ -165,7 +165,9 @@ import "yue"
 rewriteLineCol = (item)->
         item[2] = 0
         item[3] = 0
-        for i = 4, #item
+        item[4] = 0
+        item[5] = 0
+        for i = 6, #item
                 switch type item[i] when "table"
                         if item[i][1] == "comment"
                                 table.remove item, i