const std = @import("std");const file_mutation_contract = @import("../../core/tooling/file_mutation_contract.zig");const tool_dispatch = @import("../../core/tooling/tool_dispatch.zig"); const Allocator = std.mem.Allocator;const max_content_bytes: usize = 4 * 1024 * 1024; /// Typed input for the built-in write_file tool.pub const Input = struct { path: []u8, content: []u8, pub fn deinit(self: *Input, alloc: Allocator) void { alloc.free(self.path); alloc.free(self.content); self.* = .{ .path = &.{}, .content = &.{} }; }}; /// Decodes write_file JSON into an owned Input released by ToolInput.deinit.pub fn decode( ctx: tool_dispatch.DispatchContext, args_json: []const u8,) tool_dispatch.DispatchError!tool_dispatch.DecodeResult { var parsed = std.json.parseFromSlice( std.json.Value, ctx.allocator, args_json, .{}, ) catch { return .{ .failure = try ctx.allocator.dupe( u8, "write_file arguments must be valid JSON", ) }; }; defer parsed.deinit(); if (parsed.value != .object) { return .{ .failure = try ctx.allocator.dupe( u8, "write_file arguments must be an object", ) }; } const path_value = parsed.value.object.get("path") orelse { return .{ .failure = try ctx.allocator.dupe( u8, "write_file requires string field \"path\"", ) }; }; if (path_value != .string) { return .{ .failure = try ctx.allocator.dupe( u8, "write_file field \"path\" must be a string", ) }; } const content_value = parsed.value.object.get("content") orelse { return .{ .failure = try ctx.allocator.dupe( u8, "write_file requires string field \"content\"", ) }; }; if (content_value != .string) { return .{ .failure = try ctx.allocator.dupe( u8, "write_file field \"content\" must be a string", ) }; } const input = try ctx.allocator.create(Input); errdefer ctx.allocator.destroy(input); const owned_path = try ctx.allocator.dupe(u8, path_value.string); errdefer ctx.allocator.free(owned_path); const owned_content = try ctx.allocator.dupe(u8, content_value.string); errdefer ctx.allocator.free(owned_content); input.* = .{ .path = owned_path, .content = owned_content, }; return .{ .input = .{ .ptr = input, .deinit_fn = inputDeinit } };} fn inputDeinit(ptr: *anyopaque, alloc: Allocator) void { const input: *Input = @ptrCast(@alignCast(ptr)); input.deinit(alloc); alloc.destroy(input);} pub fn takeFileMutationInput( tool_input: tool_dispatch.ToolInput, alloc: Allocator,) file_mutation_contract.FileMutationInput { const input = tool_input.as(Input); const moved = file_mutation_contract.WriteInput{ .path = input.path, .content = input.content, }; alloc.destroy(input); return .{ .write = moved };} pub fn validate( ctx: tool_dispatch.DispatchContext, tool_input: tool_dispatch.ToolInput,) tool_dispatch.DispatchError!?[]u8 { const input = tool_input.as(Input); if (input.path.len > std.Io.Dir.max_path_bytes) { return try ctx.allocator.dupe( u8, "file mutation preparation failed: path exceeds the preparation limit", ); } if (input.content.len > max_content_bytes) { return try ctx.allocator.dupe( u8, "write_file failed: content exceeds the 4 MiB preparation limit", ); } return null;} pub fn call( ctx: tool_dispatch.DispatchContext, _: tool_dispatch.ToolInput,) tool_dispatch.DispatchError!tool_dispatch.ToolResult { return .{ .failure = try ctx.allocator.dupe( u8, "write_file execution requires canonical tool runtime authorization", ) };} /// Reports that write_file mutates filesystem state.pub fn readsOnly(_: tool_dispatch.ToolInput) bool { return false;} /// Reports that write_file can destroy prior file content.pub fn isIrreversible(_: tool_dispatch.ToolInput) bool { return true;} fn noopInputDeinit(_: *anyopaque, _: Allocator) void {} test "write_file decodes invalid argument shapes as failures" { const cases = [_]struct { json: []const u8, reason: []const u8, }{ .{ .json = "{", .reason = "write_file arguments must be valid JSON" }, .{ .json = "[]", .reason = "write_file arguments must be an object" }, .{ .json = "{\"content\":\"x\"}", .reason = "write_file requires string field \"path\"" }, .{ .json = "{\"path\":1,\"content\":\"x\"}", .reason = "write_file field \"path\" must be a string" }, .{ .json = "{\"path\":\"/tmp/x\"}", .reason = "write_file requires string field \"content\"" }, .{ .json = "{\"path\":\"/tmp/x\",\"content\":1}", .reason = "write_file field \"content\" must be a string" }, }; for (cases) |case| { const decoded = try decode( .{ .allocator = std.testing.allocator }, case.json, ); switch (decoded) { .failure => |reason| { defer std.testing.allocator.free(reason); try std.testing.expectEqualStrings(case.reason, reason); }, .input => |input| { input.deinit(std.testing.allocator); return error.TestExpectedDecodeFailure; }, } }} test "write_file decodes owned typed input" { const decoded = try decode( .{ .allocator = std.testing.allocator }, "{\"path\":\"file.txt\",\"content\":\"hello\\n\"}", ); const erased = switch (decoded) { .input => |input| input, .failure => |reason| { defer std.testing.allocator.free(reason); return error.TestExpectedDecodedInput; }, }; defer erased.deinit(std.testing.allocator); const input = erased.as(Input); try std.testing.expectEqualStrings("file.txt", input.path); try std.testing.expectEqualStrings("hello\n", input.content); try std.testing.expect( try validate(.{ .allocator = std.testing.allocator }, erased) == null, );} test "write_file validation enforces path and content preparation limits" { const alloc = std.testing.allocator; const oversized_path = try alloc.alloc(u8, std.Io.Dir.max_path_bytes + 1); defer alloc.free(oversized_path); @memset(oversized_path, 'p'); const oversized_content = try alloc.alloc(u8, 4 * 1024 * 1024 + 1); defer alloc.free(oversized_content); @memset(oversized_content, 'x'); const cases = [_]struct { input: Input, reason: []const u8, }{ .{ .input = .{ .path = oversized_path, .content = @constCast("content"), }, .reason = "file mutation preparation failed: path exceeds the preparation limit", }, .{ .input = .{ .path = @constCast("file.txt"), .content = oversized_content, }, .reason = "write_file failed: content exceeds the 4 MiB preparation limit", }, }; for (cases) |case| { var input = case.input; const erased = tool_dispatch.ToolInput{ .ptr = &input, .deinit_fn = noopInputDeinit, }; const reason = try validate(.{ .allocator = alloc }, erased) orelse return error.TestExpectedValidationFailure; defer alloc.free(reason); try std.testing.expectEqualStrings(case.reason, reason); }}
const std = @import("std");
const file_mutation_contract = @import("../../core/tooling/file_mutation_contract.zig");
const tool_dispatch = @import("../../core/tooling/tool_dispatch.zig");
const Allocator = std.mem.Allocator;
const max_content_bytes: usize = 4 * 1024 * 1024;
/// Typed input for the built-in write_file tool.
pub const Input = struct {
path: []u8,
content: []u8,
pub fn deinit(self: *Input, alloc: Allocator) void {
alloc.free(self.path);
alloc.free(self.content);
self.* = .{ .path = &.{}, .content = &.{} };
}
};
/// Decodes write_file JSON into an owned Input released by ToolInput.deinit.
pub fn decode(
ctx: tool_dispatch.DispatchContext,
args_json: []const u8,
) tool_dispatch.DispatchError!tool_dispatch.DecodeResult {
var parsed = std.json.parseFromSlice(
std.json.Value,
ctx.allocator,
args_json,
.{},
) catch {
return .{ .failure = try ctx.allocator.dupe(
u8,
"write_file arguments must be valid JSON",
) };
};
defer parsed.deinit();
if (parsed.value != .object) {
return .{ .failure = try ctx.allocator.dupe(
u8,
"write_file arguments must be an object",
) };
}
const path_value = parsed.value.object.get("path") orelse {
return .{ .failure = try ctx.allocator.dupe(
u8,
"write_file requires string field \"path\"",
) };
};
if (path_value != .string) {
return .{ .failure = try ctx.allocator.dupe(
u8,
"write_file field \"path\" must be a string",
) };
}
const content_value = parsed.value.object.get("content") orelse {
return .{ .failure = try ctx.allocator.dupe(
u8,
"write_file requires string field \"content\"",
) };
};
if (content_value != .string) {
return .{ .failure = try ctx.allocator.dupe(
u8,
"write_file field \"content\" must be a string",
) };
}
const input = try ctx.allocator.create(Input);
errdefer ctx.allocator.destroy(input);
const owned_path = try ctx.allocator.dupe(u8, path_value.string);
errdefer ctx.allocator.free(owned_path);
const owned_content = try ctx.allocator.dupe(u8, content_value.string);
errdefer ctx.allocator.free(owned_content);
input.* = .{
.path = owned_path,
.content = owned_content,
};
return .{ .input = .{ .ptr = input, .deinit_fn = inputDeinit } };
}
fn inputDeinit(ptr: *anyopaque, alloc: Allocator) void {
const input: *Input = @ptrCast(@alignCast(ptr));
input.deinit(alloc);
alloc.destroy(input);
}
pub fn takeFileMutationInput(
tool_input: tool_dispatch.ToolInput,
alloc: Allocator,
) file_mutation_contract.FileMutationInput {
const input = tool_input.as(Input);
const moved = file_mutation_contract.WriteInput{
.path = input.path,
.content = input.content,
};
alloc.destroy(input);
return .{ .write = moved };
}
pub fn validate(
ctx: tool_dispatch.DispatchContext,
tool_input: tool_dispatch.ToolInput,
) tool_dispatch.DispatchError!?[]u8 {
const input = tool_input.as(Input);
if (input.path.len > std.Io.Dir.max_path_bytes) {
return try ctx.allocator.dupe(
u8,
"file mutation preparation failed: path exceeds the preparation limit",
);
}
if (input.content.len > max_content_bytes) {
return try ctx.allocator.dupe(
u8,
"write_file failed: content exceeds the 4 MiB preparation limit",
);
}
return null;
}
pub fn call(
ctx: tool_dispatch.DispatchContext,
_: tool_dispatch.ToolInput,
) tool_dispatch.DispatchError!tool_dispatch.ToolResult {
return .{ .failure = try ctx.allocator.dupe(
u8,
"write_file execution requires canonical tool runtime authorization",
) };
}
/// Reports that write_file mutates filesystem state.
pub fn readsOnly(_: tool_dispatch.ToolInput) bool {
return false;
}
/// Reports that write_file can destroy prior file content.
pub fn isIrreversible(_: tool_dispatch.ToolInput) bool {
return true;
}
fn noopInputDeinit(_: *anyopaque, _: Allocator) void {}
test "write_file decodes invalid argument shapes as failures" {
const cases = [_]struct {
json: []const u8,
reason: []const u8,
}{
.{ .json = "{", .reason = "write_file arguments must be valid JSON" },
.{ .json = "[]", .reason = "write_file arguments must be an object" },
.{ .json = "{\"content\":\"x\"}", .reason = "write_file requires string field \"path\"" },
.{ .json = "{\"path\":1,\"content\":\"x\"}", .reason = "write_file field \"path\" must be a string" },
.{ .json = "{\"path\":\"/tmp/x\"}", .reason = "write_file requires string field \"content\"" },
.{ .json = "{\"path\":\"/tmp/x\",\"content\":1}", .reason = "write_file field \"content\" must be a string" },
};
for (cases) |case| {
const decoded = try decode(
.{ .allocator = std.testing.allocator },
case.json,
);
switch (decoded) {
.failure => |reason| {
defer std.testing.allocator.free(reason);
try std.testing.expectEqualStrings(case.reason, reason);
},
.input => |input| {
input.deinit(std.testing.allocator);
return error.TestExpectedDecodeFailure;
},
}
}
}
test "write_file decodes owned typed input" {
const decoded = try decode(
.{ .allocator = std.testing.allocator },
"{\"path\":\"file.txt\",\"content\":\"hello\\n\"}",
);
const erased = switch (decoded) {
.input => |input| input,
.failure => |reason| {
defer std.testing.allocator.free(reason);
return error.TestExpectedDecodedInput;
},
};
defer erased.deinit(std.testing.allocator);
const input = erased.as(Input);
try std.testing.expectEqualStrings("file.txt", input.path);
try std.testing.expectEqualStrings("hello\n", input.content);
try std.testing.expect(
try validate(.{ .allocator = std.testing.allocator }, erased) == null,
);
}
test "write_file validation enforces path and content preparation limits" {
const alloc = std.testing.allocator;
const oversized_path = try alloc.alloc(u8, std.Io.Dir.max_path_bytes + 1);
defer alloc.free(oversized_path);
@memset(oversized_path, 'p');
const oversized_content = try alloc.alloc(u8, 4 * 1024 * 1024 + 1);
defer alloc.free(oversized_content);
@memset(oversized_content, 'x');
const cases = [_]struct {
input: Input,
reason: []const u8,
}{
.{
.input = .{
.path = oversized_path,
.content = @constCast("content"),
},
.reason = "file mutation preparation failed: path exceeds the preparation limit",
},
.{
.input = .{
.path = @constCast("file.txt"),
.content = oversized_content,
},
.reason = "write_file failed: content exceeds the 4 MiB preparation limit",
},
};
for (cases) |case| {
var input = case.input;
const erased = tool_dispatch.ToolInput{
.ptr = &input,
.deinit_fn = noopInputDeinit,
};
const reason = try validate(.{ .allocator = alloc }, erased) orelse
return error.TestExpectedValidationFailure;
defer alloc.free(reason);
try std.testing.expectEqualStrings(case.reason, reason);
}
}