mymarkdown

commit 200c1f7c82ca4056761cd0d0ed2e368eec504501
parent 71831825ee34cefa215e26379e45c96d9b9f4e14
Author: gracefu <81774659+gracefuu@users.noreply.github.com>
Date:   Thu, 22 May 2025 14:01:12 +0800

Do a bit of fuzzing

Diffstat:
M
src/AstGen3.zig
 | 
2
+-
M
src/main.zig
 | 
10
+++++-----
M
src/test.zig
 | 
36
+++++++++++++++++++++++++++++++++---

3 files changed, 39 insertions(+), 9 deletions(-)
diff --git a/src/AstGen3.zig b/src/AstGen3.zig
@@ -544,7 +544,7 @@ fn parseColumn(
                 },
 
                 '*' => {
-                    if (std.mem.eql(u8, line.toUnpaddedSlice()[0..3], "***")) {
+                    if (std.mem.eql(u8, line.toUnpaddedSlice().ptr[0..3], "***")) {
                         const after_stars = line.sliceOpen(3);
                         if (after_stars.len == after_stars.indexOfNotSpaceOrTab()) {
                             self.scanner.advance();
diff --git a/src/main.zig b/src/main.zig
@@ -9,16 +9,16 @@ fn readInput(gpa: std.mem.Allocator, arena: std.mem.Allocator) !std.ArrayList(u8
     defer tracy_frame.end();
     if (stdin.stat()) |stat| {
         if (stat.size > 0) {
-            var al: std.ArrayList(u8) = try .initCapacity(arena, stat.size + mymarkdown.PADDING);
-            try stdin.reader().readAllArrayList(&al, std.math.maxInt(u32) - mymarkdown.PADDING);
-            try al.appendNTimes('\n', mymarkdown.PADDING);
+            var al: std.ArrayList(u8) = try .initCapacity(arena, stat.size + mymarkdown.PADDING + 1);
+            try stdin.reader().readAllArrayList(&al, std.math.maxInt(u32) - mymarkdown.PADDING - 1);
+            try al.appendNTimes('\n', mymarkdown.PADDING + 1);
             return al;
         }
     } else |_| {}
     var al: std.ArrayList(u8) = try .initCapacity(gpa, 4096);
     errdefer al.deinit();
-    try stdin.reader().readAllArrayList(&al, std.math.maxInt(u32) - mymarkdown.PADDING);
-    try al.appendNTimes('\n', mymarkdown.PADDING);
+    try stdin.reader().readAllArrayList(&al, std.math.maxInt(u32) - mymarkdown.PADDING - 1);
+    try al.appendNTimes('\n', mymarkdown.PADDING + 1);
     return al;
 }
 
diff --git a/src/test.zig b/src/test.zig
@@ -12,11 +12,23 @@ fn readFile(gpa: std.mem.Allocator, path: []const u8) !std.ArrayList(u8) {
     const input_file = try std.fs.cwd().openFile(path, .{});
     defer input_file.close();
     const file_size = (try input_file.stat()).size;
-    try input_instance.ensureTotalCapacity(file_size + PADDING);
-    try input_file.reader().readAllArrayList(&input_instance, std.math.maxInt(u32) - PADDING);
+    try input_instance.ensureTotalCapacity(file_size + PADDING + 1);
+    try input_file.reader().readAllArrayList(&input_instance, std.math.maxInt(u32) - PADDING - 1);
     return input_instance;
 }
 
+fn testForCrashes(gpa: std.mem.Allocator, input: []const u8) !void {
+    const padded_input = try std.mem.concat(gpa, u8, &.{ input, "\n" ** (PADDING + 1) });
+    defer gpa.free(padded_input);
+
+    const ast = try parse3(gpa, null, padded_input);
+    defer ast.deinit(gpa);
+
+    var output_instance: std.ArrayList(u8) = .init(gpa);
+    defer output_instance.deinit();
+    try ast.renderAst(output_instance.writer(), padded_input);
+}
+
 fn testSnapshot(gpa: std.mem.Allocator, path: []const u8) !void {
     return testSnapshotImpl(gpa, path);
     // std.testing.checkAllAllocationFailures(
@@ -34,7 +46,7 @@ fn testSnapshotImpl(gpa: std.mem.Allocator, path: []const u8) !void {
 
     var input_instance = try readFile(gpa, path);
     defer input_instance.deinit();
-    try input_instance.appendNTimes('\n', 128);
+    try input_instance.appendNTimes('\n', PADDING + 1);
 
     const ast = try parse3(gpa, null, input_instance.items);
     defer ast.deinit(gpa);
@@ -121,6 +133,24 @@ test "Sample" {
     try testSnapshot(std.testing.allocator, "src/test/sample.my");
 }
 
+test "fuzz" {
+    var arena_instance: std.heap.ArenaAllocator = .init(std.testing.allocator);
+    defer arena_instance.deinit();
+    const arena = arena_instance.allocator();
+    try std.testing.fuzz(std.testing.allocator, testForCrashes, .{
+        .corpus = &.{
+            // (try readFile(arena, "src/test/empty.my")).items,
+            (try readFile(arena, "src/test/paragraph.my")).items,
+            (try readFile(arena, "src/test/heading.my")).items,
+            (try readFile(arena, "src/test/quote.my")).items,
+            (try readFile(arena, "src/test/list.my")).items,
+            (try readFile(arena, "src/test/elaboration.my")).items,
+            (try readFile(arena, "src/test/thematic_break.my")).items,
+            (try readFile(arena, "src/test/sample.my")).items,
+        },
+    });
+}
+
 test "Super long line" {
     const input = try std.testing.allocator.create([(1 << 24) * 4 + PADDING + 1]u8);
     defer std.testing.allocator.destroy(input);