From 36c2b685b9ca74b90bf1e4ba590ea6579c915eef Mon Sep 17 00:00:00 2001
From: Max Brunsfeld <maxbrunsfeld@gmail.com>
Date: Wed, 4 Oct 2017 15:09:46 -0700
Subject: [PATCH] Always invalidate old chunk of text when parsing after an
 edit

---
 src/runtime/lexer.c           |  3 +++
 src/runtime/parser.c          |  2 +-
 test/helpers/spy_input.cc     |  2 +-
 test/helpers/spy_input.h      |  2 +-
 test/runtime/document_test.cc | 35 ++++++++++++++++++++++++++++++++---
 5 files changed, 38 insertions(+), 6 deletions(-)

diff --git a/src/runtime/lexer.c b/src/runtime/lexer.c
index 599bea62..a165b8a6 100644
--- a/src/runtime/lexer.c
+++ b/src/runtime/lexer.c
@@ -132,6 +132,9 @@ static inline void ts_lexer__reset(Lexer *self, Length position) {
 
 void ts_lexer_set_input(Lexer *self, TSInput input) {
   self->input = input;
+  self->chunk = 0;
+  self->chunk_start = 0;
+  self->chunk_size = 0;
   ts_lexer__reset(self, length_zero());
 }
 
diff --git a/src/runtime/parser.c b/src/runtime/parser.c
index 527b0a82..5a7dff20 100644
--- a/src/runtime/parser.c
+++ b/src/runtime/parser.c
@@ -17,7 +17,7 @@
   if (self->lexer.logger.log || self->print_debugging_graphs) {                             \
     snprintf(self->lexer.debug_buffer, TREE_SITTER_SERIALIZATION_BUFFER_SIZE, __VA_ARGS__); \
     parser__log(self);                                                                      \
-  }                                                                                         \
+  }
 
 #define LOG_STACK()                                                              \
   if (self->print_debugging_graphs) {                                            \
diff --git a/test/helpers/spy_input.cc b/test/helpers/spy_input.cc
index ae7e9c1f..01554e85 100644
--- a/test/helpers/spy_input.cc
+++ b/test/helpers/spy_input.cc
@@ -9,9 +9,9 @@ using std::string;
 using std::vector;
 
 SpyInput::SpyInput(string content, size_t chars_per_chunk) :
-  chars_per_chunk(chars_per_chunk),
   buffer(nullptr),
   byte_offset(0),
+  chars_per_chunk(chars_per_chunk),
   content(content),
   encoding(TSInputEncodingUTF8),
   ranges_read({}) {}
diff --git a/test/helpers/spy_input.h b/test/helpers/spy_input.h
index 2a15ad9b..2de1a301 100644
--- a/test/helpers/spy_input.h
+++ b/test/helpers/spy_input.h
@@ -12,7 +12,6 @@ struct SpyInputEdit {
 };
 
 class SpyInput {
-  uint32_t chars_per_chunk;
   char *buffer;
   uint32_t byte_offset;
   std::vector<SpyInputEdit> undo_stack;
@@ -31,6 +30,7 @@ class SpyInput {
   TSInputEdit undo();
   std::vector<std::string> strings_read() const;
 
+  uint32_t chars_per_chunk;
   std::string content;
   TSInputEncoding encoding;
   std::vector<std::pair<uint32_t, uint32_t>> ranges_read;
diff --git a/test/runtime/document_test.cc b/test/runtime/document_test.cc
index 138264bb..7917a152 100644
--- a/test/runtime/document_test.cc
+++ b/test/runtime/document_test.cc
@@ -15,8 +15,6 @@ TSPoint point(size_t row, size_t column) {
 
 START_TEST
 
-
-
 describe("Document", [&]() {
   TSDocument *document;
   TSNode root;
@@ -259,7 +257,7 @@ describe("Document", [&]() {
 
     before_each([&]() {
       ts_document_set_language(document, load_real_language("javascript"));
-      input = new SpyInput("{a: null};", 3);
+      input = new SpyInput("{a: null};\n", 3);
       ts_document_set_input(document, input->input());
       ts_document_parse(document);
       assert_node_string_equals(
@@ -313,6 +311,37 @@ describe("Document", [&]() {
       })));
     });
 
+    it("reports no changes when leading whitespace has changed (regression)", [&]() {
+      input->chars_per_chunk = 80;
+
+      // Insert leading whitespace
+      auto ranges = get_invalidated_ranges_for_edit([&]() {
+        return input->replace(0, 0, "\n");
+      });
+      assert_node_string_equals(
+        ts_document_root_node(document),
+        "(program (expression_statement (object (pair (property_identifier) (null)))))");
+      AssertThat(ranges, Equals(vector<TSRange>({})));
+
+      // Remove leading whitespace
+      ranges = get_invalidated_ranges_for_edit([&]() {
+        return input->undo();
+      });
+      assert_node_string_equals(
+        ts_document_root_node(document),
+        "(program (expression_statement (object (pair (property_identifier) (null)))))");
+      AssertThat(ranges, Equals(vector<TSRange>({})));
+
+      // Insert leading whitespace again
+      ranges = get_invalidated_ranges_for_edit([&]() {
+        return input->replace(0, 0, "\n");
+      });
+      assert_node_string_equals(
+        ts_document_root_node(document),
+        "(program (expression_statement (object (pair (property_identifier) (null)))))");
+      AssertThat(ranges, Equals(vector<TSRange>({})));
+    });
+
     it("reports changes when tokens have been appended", [&]() {
       // Add a second key-value pair
       auto ranges = get_invalidated_ranges_for_edit([&]() {