Skip to content

Commit

Permalink
Add tests for shell history
Browse files Browse the repository at this point in the history
  • Loading branch information
@jmbaur
jmbaur committed Jul 25, 2024
1 parent 6b85402 commit ed8403a
Showing 1 changed file with 154 additions and 122 deletions.
276 changes: 154 additions & 122 deletions src/console.zig
View file
Original file line number Diff line number Diff line change
Expand Up @@ -36,14 +36,17 @@ const NON_WORD_CHARS = std.ascii.whitespace ++ [_]u8{ '.', ';', ',' };
var out = std.io.bufferedWriter(std.io.getStdOut().writer());

const Shell = struct {
arena: std.heap.ArenaAllocator = std.heap.ArenaAllocator.init(std.heap.page_allocator),
input_cursor: usize = 0,
input_end: usize = 0,
stdin: std.fs.File.Reader = std.io.getStdIn().reader(),
input_buffer: [std.math.maxInt(u9)]u8 = undefined,
history: History(10) = .{},
history: History = .{},

pub fn deinit(self: *@This()) void {
self.history.deinit();
defer self.arena.deinit();

self.history.deinit(self.arena.allocator());
}

pub fn prompt(self: *@This(), context: ?*BootLoader) void {
Expand All @@ -55,6 +58,73 @@ const Shell = struct {
writeAllAndFlush("> ");
}

fn historyPrev(self: *@This()) bool {
if (self.history.prev()) |prev| {
@memcpy(self.input_buffer[0..prev.len], prev);
const old_end = self.input_end;

self.input_end = prev.len;
self.input_cursor = prev.len;

cursorLeft(old_end);
writeAll(self.input_buffer[0..self.input_end]);
eraseToEndOfLine();

return true;
}

return false;
}

fn historyNext(self: *@This()) bool {
if (self.history.next()) |next| {
@memcpy(self.input_buffer[0..next.len], next);
const old_end = self.input_end;

self.input_end = next.len;
self.input_cursor = next.len;

cursorLeft(old_end);
writeAll(self.input_buffer[0..self.input_end]);
eraseToEndOfLine();

return true;
} else {
// We are back out of scrolling through history, start from
// a clean slate.
cursorLeft(self.input_end);

self.input_end = 0;
self.input_cursor = 0;

eraseToEndOfLine();

return true;
}

return false;
}

fn moveLeft(self: *@This()) bool {
if (self.input_cursor > 0) {
cursorLeft(1);
self.input_cursor -|= 1;
return true;
}

return false;
}

fn moveRight(self: *@This()) bool {
if (self.input_cursor < self.input_end) {
cursorRight(1);
self.input_cursor +|= 1;
return true;
}

return false;
}

pub fn handleInput(self: *@This(), context: ?*BootLoader) !?[]const u8 {
std.debug.assert(self.input_cursor <= self.input_end);

Expand All @@ -80,15 +150,7 @@ const Shell = struct {
break :b false;
},
// C-b
0x02 => b: {
if (self.input_cursor > 0) {
cursorLeft(1);
self.input_cursor -|= 1;
break :b true;
}

break :b false;
},
0x02 => self.moveLeft(),
// C-c
0x03 => b: {
writeAll("\n");
Expand Down Expand Up @@ -117,15 +179,7 @@ const Shell = struct {
break :b false;
},
// C-f
0x06 => b: {
if (self.input_cursor < self.input_end) {
cursorRight(1);
self.input_cursor +|= 1;
break :b true;
}

break :b false;
},
0x06 => self.moveRight(),
// Bell
0x07 => false,
// C-h, Backspace
Expand Down Expand Up @@ -164,52 +218,9 @@ const Shell = struct {
break :b true;
},
// C-n
0x0e => b: {
if (self.history.next()) |next| {
@memcpy(self.input_buffer[0..next.len], next);
const old_end = self.input_end;

self.input_end = next.len;
self.input_cursor = next.len;

cursorLeft(old_end);
writeAll(self.input_buffer[0..self.input_end]);
eraseToEndOfLine();

break :b true;
} else {
// We are back out of scrolling through history, start from
// a clean slate.
cursorLeft(self.input_end);

self.input_end = 0;
self.input_cursor = 0;

eraseToEndOfLine();

break :b true;
}

break :b false;
},
0x0e => self.historyNext(),
// C-p
0x10 => b: {
if (self.history.prev()) |prev| {
@memcpy(self.input_buffer[0..prev.len], prev);
const old_end = self.input_end;

self.input_end = prev.len;
self.input_cursor = prev.len;

cursorLeft(old_end);
writeAll(self.input_buffer[0..self.input_end]);
eraseToEndOfLine();

break :b true;
}

break :b false;
},
0x10 => self.historyPrev(),
// C-r
0x12 => false,
// C-t
Expand Down Expand Up @@ -316,13 +327,13 @@ const Shell = struct {
// TODO(jared): handle these
switch (try self.stdin.readByte()) {
// Up arrow
0x41 => {},
0x41 => break :b self.historyPrev(),
// Down arrow
0x42 => {},
0x42 => break :b self.historyNext(),
// Right arrow
0x43 => {},
0x43 => break :b self.moveRight(),
// Left arrow
0x44 => {},
0x44 => break :b self.moveLeft(),
else => {},
}
},
Expand Down Expand Up @@ -446,8 +457,6 @@ const Shell = struct {
}

if (done) {
self.history.resetIndex();

const input = self.input_buffer[0..self.input_end];

self.input_cursor = 0;
Expand All @@ -465,78 +474,101 @@ const Shell = struct {
return null;
}

fn History(comptime size: u8) type {
return struct {
arena: std.heap.ArenaAllocator = std.heap.ArenaAllocator.init(std.heap.page_allocator),

index: ?usize = null,
items: [size]?[]const u8 = undefined,
const History = struct {
const size = 10;

pub fn deinit(self: *@This()) void {
self.arena.deinit();
}
index: ?usize = null,
items: [size]?[]const u8 = undefined,

pub fn resetIndex(self: *@This()) void {
self.index = null;
pub fn deinit(self: *@This(), allocator: std.mem.Allocator) void {
for (self.items) |item| {
if (item) |_item| {
allocator.free(_item);
}
}
}

pub fn push(self: *@This(), value: []const u8) !void {
for (1..self.items.len) |i| {
const index = self.items.len - i;

const old = self.items[index];
const new = self.items[index - 1];
pub fn resetIndex(self: *@This()) void {
self.index = null;
}

// free the last element
if (index == self.items.len - 1) {
if (old) |_old| {
self.arena.allocator().free(_old);
}
pub fn push(
self: *@This(),
value: []const u8,
allocator: std.mem.Allocator,
) !void {
for (1..self.items.len) |i| {
const index = self.items.len - i;

const old = self.items[index];
const new = self.items[index - 1];

// free the last element
if (index == self.items.len - 1) {
if (old) |_old| {
allocator.free(_old);
}

self.items[index] = new;
}

// set new first item
self.items[0] = try self.arena.allocator().dupe(u8, value);
self.items[index] = new;
}

pub fn prev(self: *@This()) ?[]const u8 {
const new_index = if (self.index) |index| index +| 1 else 0;

if (new_index >= size) {
return null;
}
// set new first item
self.items[0] = try allocator.dupe(u8, value);
self.resetIndex();
}

std.debug.assert(new_index < size);
if (self.items[new_index]) |item| {
self.index = new_index;
return item;
}
pub fn prev(self: *@This()) ?[]const u8 {
const new_index = if (self.index) |index| index +| 1 else 0;

if (new_index >= size) {
return null;
}

pub fn next(self: *@This()) ?[]const u8 {
const new_index = (self.index orelse return null) -| 1;
std.debug.assert(new_index < size);
if (self.items[new_index]) |item| {
self.index = new_index;
return item;
}

if (self.index == 0) {
self.resetIndex();
return null;
}
return null;
}

std.debug.assert(new_index < size);
if (self.items[new_index]) |item| {
self.index = new_index;
return item;
}
pub fn next(self: *@This()) ?[]const u8 {
const new_index = (self.index orelse return null) -| 1;

if (self.index == 0) {
self.resetIndex();
return null;
}
};
}

std.debug.assert(new_index < size);
if (self.items[new_index]) |item| {
self.index = new_index;
return item;
}

return null;
}
};
};

test "shell history" {
var history = Shell.History{};
defer history.deinit(std.testing.allocator);

try std.testing.expect(history.prev() == null);
try std.testing.expect(history.next() == null);
history.push("foo", std.testing.allocator) catch unreachable;
try std.testing.expectEqualStrings("foo", history.prev() orelse unreachable);
try std.testing.expect(history.prev() == null);
history.push("bar", std.testing.allocator) catch unreachable;
try std.testing.expectEqualStrings("bar", history.prev() orelse unreachable);
try std.testing.expectEqualStrings("foo", history.prev() orelse unreachable);
try std.testing.expectEqualStrings("bar", history.next() orelse unreachable);
try std.testing.expect(history.next() == null);
}

arena: std.heap.ArenaAllocator = std.heap.ArenaAllocator.init(std.heap.page_allocator),
shell: Shell = .{},
context: ?*BootLoader = null,
Expand Down Expand Up @@ -658,7 +690,7 @@ pub fn handleStdin(self: *Console, boot_loaders: []*BootLoader) !?Event {
}

self.shell.prompt(self.context);
try self.shell.history.push(user_input);
try self.shell.history.push(user_input, self.shell.arena.allocator());
}

return null;
Expand Down

0 comments on commit ed8403a

Please sign in to comment.