extract deepEqual

src/config/Config.zig

@@ -17,6 +17,7 @@ const assert = @import("../quirks.zig").inlineAssert;
 const Allocator = std.mem.Allocator;
 const ArenaAllocator = std.heap.ArenaAllocator;
 const global_state = &@import("../global.zig").state;
+const deepEqual = @import("../datastruct/comparison.zig").deepEqual;
 const fontpkg = @import("../font/main.zig");
 const inputpkg = @import("../input.zig");
 const internal_os = @import("../os/main.zig");
@@ -4120,7 +4121,7 @@ pub fn changeConditionalState(
 
             // Conditional set contains the keys that this config uses. So we
             // only continue if we use this key.
-            if (self._conditional_set.contains(key) and !equalField(
+            if (self._conditional_set.contains(key) and !deepEqual(
                 @TypeOf(@field(self._conditional_state, field.name)),
                 @field(self._conditional_state, field.name),
                 @field(new, field.name),
@@ -4826,7 +4827,7 @@ pub fn changed(self: *const Config, new: *const Config, comptime key: Key) bool
 
     const old_value = @field(self, field.name);
     const new_value = @field(new, field.name);
-    return !equalField(field.type, old_value, new_value);
+    return !deepEqual(field.type, old_value, new_value);
 }
 
 /// This yields a key for every changed field between old and new.
@@ -4854,91 +4855,6 @@ pub const ChangeIterator = struct {
     }
 };
 
-/// A config-specific helper to determine if two values of the same
-/// type are equal. This isn't the same as std.mem.eql or std.testing.equals
-/// because we expect structs to implement their own equality.
-///
-/// This also doesn't support ALL Zig types, because we only add to it
-/// as we need types for the config.
-fn equalField(comptime T: type, old: T, new: T) bool {
-    // Do known named types first
-    switch (T) {
-        inline []const u8,
-        [:0]const u8,
-        => return std.mem.eql(u8, old, new),
-
-        []const [:0]const u8,
-        => {
-            if (old.len != new.len) return false;
-            for (old, new) |a, b| {
-                if (!std.mem.eql(u8, a, b)) return false;
-            }
-
-            return true;
-        },
-
-        else => {},
-    }
-
-    // Back into types of types
-    switch (@typeInfo(T)) {
-        .void => return true,
-
-        inline .bool,
-        .int,
-        .float,
-        .@"enum",
-        => return old == new,
-
-        .optional => |info| {
-            if (old == null and new == null) return true;
-            if (old == null or new == null) return false;
-            return equalField(info.child, old.?, new.?);
-        },
-
-        .@"struct" => |info| {
-            if (@hasDecl(T, "equal")) return old.equal(new);
-
-            // If a struct doesn't declare an "equal" function, we fall back
-            // to a recursive field-by-field compare.
-            inline for (info.fields) |field_info| {
-                if (!equalField(
-                    field_info.type,
-                    @field(old, field_info.name),
-                    @field(new, field_info.name),
-                )) return false;
-            }
-            return true;
-        },
-
-        .@"union" => |info| {
-            if (@hasDecl(T, "equal")) return old.equal(new);
-
-            const tag_type = info.tag_type.?;
-            const old_tag = std.meta.activeTag(old);
-            const new_tag = std.meta.activeTag(new);
-            if (old_tag != new_tag) return false;
-
-            inline for (info.fields) |field_info| {
-                if (@field(tag_type, field_info.name) == old_tag) {
-                    return equalField(
-                        field_info.type,
-                        @field(old, field_info.name),
-                        @field(new, field_info.name),
-                    );
-                }
-            }
-
-            unreachable;
-        },
-
-        else => {
-            @compileLog(T);
-            @compileError("unsupported field type");
-        },
-    }
-}
-
 /// This runs a heuristic to determine if we are likely running
 /// Ghostty in a CLI environment. We need this to change some behaviors.
 /// We should keep the set of behaviors that depend on this as small
@@ -6885,7 +6801,7 @@ pub const Keybinds = struct {
                     const self_leaf = self_entry.value_ptr.*.leaf;
                     const other_leaf = other_entry.value_ptr.*.leaf;
 
-                    if (!equalField(
+                    if (!deepEqual(
                         inputpkg.Binding.Set.Leaf,
                         self_leaf,
                         other_leaf,
@@ -6899,7 +6815,7 @@ pub const Keybinds = struct {
                     if (self_chain.flags != other_chain.flags) return false;
                     if (self_chain.actions.items.len != other_chain.actions.items.len) return false;
                     for (self_chain.actions.items, other_chain.actions.items) |a1, a2| {
-                        if (!equalField(
+                        if (!deepEqual(
                             inputpkg.Binding.Action,
                             a1,
                             a2,

src/datastruct/comparison.zig

@@ -1,11 +1,102 @@
 // The contents of this file is largely based on testing.zig from the Zig 0.15.1
 // stdlib, distributed under the MIT license, copyright (c) Zig contributors
 const std = @import("std");
+const testing = std.testing;
+
+/// A deep equality comparison function that works for most types. We
+/// add types as necessary. It defers to `equal` decls on types that support
+/// decls.
+pub fn deepEqual(comptime T: type, old: T, new: T) bool {
+    // Do known named types first
+    switch (T) {
+        inline []const u8,
+        [:0]const u8,
+        => return std.mem.eql(u8, old, new),
+
+        []const [:0]const u8,
+        => {
+            if (old.len != new.len) return false;
+            for (old, new) |a, b| {
+                if (!std.mem.eql(u8, a, b)) return false;
+            }
+
+            return true;
+        },
+
+        else => {},
+    }
+
+    // Back into types of types
+    switch (@typeInfo(T)) {
+        .void => return true,
+
+        inline .bool,
+        .int,
+        .float,
+        .@"enum",
+        => return old == new,
+
+        .optional => |info| {
+            if (old == null and new == null) return true;
+            if (old == null or new == null) return false;
+            return deepEqual(info.child, old.?, new.?);
+        },
+
+        .array => |info| for (old, new) |old_elem, new_elem| {
+            if (!deepEqual(
+                info.child,
+                old_elem,
+                new_elem,
+            )) return false;
+        } else return true,
+
+        .@"struct" => |info| {
+            if (@hasDecl(T, "equal")) return old.equal(new);
+
+            // If a struct doesn't declare an "equal" function, we fall back
+            // to a recursive field-by-field compare.
+            inline for (info.fields) |field_info| {
+                if (!deepEqual(
+                    field_info.type,
+                    @field(old, field_info.name),
+                    @field(new, field_info.name),
+                )) return false;
+            }
+            return true;
+        },
+
+        .@"union" => |info| {
+            if (@hasDecl(T, "equal")) return old.equal(new);
+
+            const tag_type = info.tag_type.?;
+            const old_tag = std.meta.activeTag(old);
+            const new_tag = std.meta.activeTag(new);
+            if (old_tag != new_tag) return false;
+
+            inline for (info.fields) |field_info| {
+                if (@field(tag_type, field_info.name) == old_tag) {
+                    return deepEqual(
+                        field_info.type,
+                        @field(old, field_info.name),
+                        @field(new, field_info.name),
+                    );
+                }
+            }
+
+            unreachable;
+        },
+
+        else => {
+            @compileLog(T);
+            @compileError("unsupported field type");
+        },
+    }
+}
 
 /// Generic, recursive equality testing utility using approximate comparison for
 /// floats and equality for everything else
 ///
-/// Based on `std.testing.expectEqual` and `std.testing.expectEqualSlices`.
+/// Based on `testing.expectEqual` and `testing.expectEqualSlices`.
 ///
 /// The relative tolerance is currently hardcoded to `sqrt(eps(float_type))`.
 pub inline fn expectApproxEqual(expected: anytype, actual: anytype) !void {
@@ -59,7 +150,7 @@ fn expectApproxEqualInner(comptime T: type, expected: T, actual: T) !void {
             if (union_info.tag_type == null) {
                 // untagged unions can only be compared bitwise,
                 // so expectEqual is all we need
-                std.testing.expectEqual(expected, actual) catch {
+                testing.expectEqual(expected, actual) catch {
                     return error.TestExpectedApproxEqual;
                 };
             }
@@ -69,7 +160,7 @@ fn expectApproxEqualInner(comptime T: type, expected: T, actual: T) !void {
             const expectedTag = @as(Tag, expected);
             const actualTag = @as(Tag, actual);
 
-            std.testing.expectEqual(expectedTag, actualTag) catch {
+            testing.expectEqual(expectedTag, actualTag) catch {
                 return error.TestExpectedApproxEqual;
             };
 
@@ -84,23 +175,23 @@ fn expectApproxEqualInner(comptime T: type, expected: T, actual: T) !void {
             };
             // we only reach this point if there's at least one null or error,
             // in which case expectEqual is all we need
-            std.testing.expectEqual(expected, actual) catch {
+            testing.expectEqual(expected, actual) catch {
                 return error.TestExpectedApproxEqual;
             };
         },
 
         // fall back to expectEqual for everything else
-        else => std.testing.expectEqual(expected, actual) catch {
+        else => testing.expectEqual(expected, actual) catch {
             return error.TestExpectedApproxEqual;
         },
     }
 }
 
-/// Copy of std.testing.print (not public)
+/// Copy of testing.print (not public)
 fn print(comptime fmt: []const u8, args: anytype) void {
     if (@inComptime()) {
         @compileError(std.fmt.comptimePrint(fmt, args));
-    } else if (std.testing.backend_can_print) {
+    } else if (testing.backend_can_print) {
         std.debug.print(fmt, args);
     }
 }
@@ -145,3 +236,195 @@ test "expectApproxEqual struct" {
 
     try expectApproxEqual(a, b);
 }
+
+test "deepEqual void" {
+    try testing.expect(deepEqual(void, {}, {}));
+}
+
+test "deepEqual bool" {
+    try testing.expect(deepEqual(bool, true, true));
+    try testing.expect(deepEqual(bool, false, false));
+    try testing.expect(!deepEqual(bool, true, false));
+    try testing.expect(!deepEqual(bool, false, true));
+}
+
+test "deepEqual int" {
+    try testing.expect(deepEqual(i32, 42, 42));
+    try testing.expect(deepEqual(i32, -100, -100));
+    try testing.expect(!deepEqual(i32, 42, 43));
+    try testing.expect(deepEqual(u64, 0, 0));
+    try testing.expect(!deepEqual(u64, 0, 1));
+}
+
+test "deepEqual float" {
+    try testing.expect(deepEqual(f32, 1.0, 1.0));
+    try testing.expect(!deepEqual(f32, 1.0, 1.1));
+    try testing.expect(deepEqual(f64, 3.14159, 3.14159));
+    try testing.expect(!deepEqual(f64, 3.14159, 3.14158));
+}
+
+test "deepEqual enum" {
+    const Color = enum { red, green, blue };
+    try testing.expect(deepEqual(Color, .red, .red));
+    try testing.expect(deepEqual(Color, .blue, .blue));
+    try testing.expect(!deepEqual(Color, .red, .green));
+    try testing.expect(!deepEqual(Color, .green, .blue));
+}
+
+test "deepEqual []const u8" {
+    try testing.expect(deepEqual([]const u8, "hello", "hello"));
+    try testing.expect(deepEqual([]const u8, "", ""));
+    try testing.expect(!deepEqual([]const u8, "hello", "world"));
+    try testing.expect(!deepEqual([]const u8, "hello", "hell"));
+    try testing.expect(!deepEqual([]const u8, "hello", "hello!"));
+}
+
+test "deepEqual [:0]const u8" {
+    try testing.expect(deepEqual([:0]const u8, "foo", "foo"));
+    try testing.expect(!deepEqual([:0]const u8, "foo", "bar"));
+    try testing.expect(!deepEqual([:0]const u8, "foo", "fo"));
+}
+
+test "deepEqual []const [:0]const u8" {
+    const a: []const [:0]const u8 = &.{ "one", "two", "three" };
+    const b: []const [:0]const u8 = &.{ "one", "two", "three" };
+    const c: []const [:0]const u8 = &.{ "one", "two" };
+    const d: []const [:0]const u8 = &.{ "one", "two", "four" };
+    const e: []const [:0]const u8 = &.{};
+
+    try testing.expect(deepEqual([]const [:0]const u8, a, b));
+    try testing.expect(!deepEqual([]const [:0]const u8, a, c));
+    try testing.expect(!deepEqual([]const [:0]const u8, a, d));
+    try testing.expect(deepEqual([]const [:0]const u8, e, e));
+    try testing.expect(!deepEqual([]const [:0]const u8, a, e));
+}
+
+test "deepEqual optional" {
+    try testing.expect(deepEqual(?i32, null, null));
+    try testing.expect(deepEqual(?i32, 42, 42));
+    try testing.expect(!deepEqual(?i32, null, 42));
+    try testing.expect(!deepEqual(?i32, 42, null));
+    try testing.expect(!deepEqual(?i32, 42, 43));
+}
+
+test "deepEqual optional nested" {
+    const Nested = struct { x: i32, y: i32 };
+    try testing.expect(deepEqual(?Nested, null, null));
+    try testing.expect(deepEqual(?Nested, .{ .x = 1, .y = 2 }, .{ .x = 1, .y = 2 }));
+    try testing.expect(!deepEqual(?Nested, .{ .x = 1, .y = 2 }, .{ .x = 1, .y = 3 }));
+    try testing.expect(!deepEqual(?Nested, .{ .x = 1, .y = 2 }, null));
+}
+
+test "deepEqual array" {
+    try testing.expect(deepEqual([3]i32, .{ 1, 2, 3 }, .{ 1, 2, 3 }));
+    try testing.expect(!deepEqual([3]i32, .{ 1, 2, 3 }, .{ 1, 2, 4 }));
+    try testing.expect(!deepEqual([3]i32, .{ 1, 2, 3 }, .{ 0, 2, 3 }));
+    try testing.expect(deepEqual([0]i32, .{}, .{}));
+}
+
+test "deepEqual nested array" {
+    const a = [2][2]i32{ .{ 1, 2 }, .{ 3, 4 } };
+    const b = [2][2]i32{ .{ 1, 2 }, .{ 3, 4 } };
+    const c = [2][2]i32{ .{ 1, 2 }, .{ 3, 5 } };
+
+    try testing.expect(deepEqual([2][2]i32, a, b));
+    try testing.expect(!deepEqual([2][2]i32, a, c));
+}
+
+test "deepEqual struct" {
+    const Point = struct { x: i32, y: i32 };
+    try testing.expect(deepEqual(Point, .{ .x = 10, .y = 20 }, .{ .x = 10, .y = 20 }));
+    try testing.expect(!deepEqual(Point, .{ .x = 10, .y = 20 }, .{ .x = 10, .y = 21 }));
+    try testing.expect(!deepEqual(Point, .{ .x = 10, .y = 20 }, .{ .x = 11, .y = 20 }));
+}
+
+test "deepEqual struct nested" {
+    const Inner = struct { value: i32 };
+    const Outer = struct { a: Inner, b: Inner };
+
+    const x = Outer{ .a = .{ .value = 1 }, .b = .{ .value = 2 } };
+    const y = Outer{ .a = .{ .value = 1 }, .b = .{ .value = 2 } };
+    const z = Outer{ .a = .{ .value = 1 }, .b = .{ .value = 3 } };
+
+    try testing.expect(deepEqual(Outer, x, y));
+    try testing.expect(!deepEqual(Outer, x, z));
+}
+
+test "deepEqual struct with equal decl" {
+    const Custom = struct {
+        value: i32,
+
+        pub fn equal(self: @This(), other: @This()) bool {
+            return @mod(self.value, 10) == @mod(other.value, 10);
+        }
+    };
+
+    try testing.expect(deepEqual(Custom, .{ .value = 5 }, .{ .value = 15 }));
+    try testing.expect(deepEqual(Custom, .{ .value = 100 }, .{ .value = 0 }));
+    try testing.expect(!deepEqual(Custom, .{ .value = 5 }, .{ .value = 6 }));
+}
+
+test "deepEqual union" {
+    const Value = union(enum) {
+        int: i32,
+        float: f32,
+        none,
+    };
+
+    try testing.expect(deepEqual(Value, .{ .int = 42 }, .{ .int = 42 }));
+    try testing.expect(!deepEqual(Value, .{ .int = 42 }, .{ .int = 43 }));
+    try testing.expect(!deepEqual(Value, .{ .int = 42 }, .{ .float = 42.0 }));
+    try testing.expect(deepEqual(Value, .none, .none));
+    try testing.expect(!deepEqual(Value, .none, .{ .int = 0 }));
+}
+
+test "deepEqual union with equal decl" {
+    const Value = union(enum) {
+        num: i32,
+        str: []const u8,
+
+        pub fn equal(self: @This(), other: @This()) bool {
+            return switch (self) {
+                .num => |n| switch (other) {
+                    .num => |m| @mod(n, 10) == @mod(m, 10),
+                    else => false,
+                },
+                .str => |s| switch (other) {
+                    .str => |t| s.len == t.len,
+                    else => false,
+                },
+            };
+        }
+    };
+
+    try testing.expect(deepEqual(Value, .{ .num = 5 }, .{ .num = 25 }));
+    try testing.expect(!deepEqual(Value, .{ .num = 5 }, .{ .num = 6 }));
+    try testing.expect(deepEqual(Value, .{ .str = "abc" }, .{ .str = "xyz" }));
+    try testing.expect(!deepEqual(Value, .{ .str = "abc" }, .{ .str = "ab" }));
+}
+
+test "deepEqual array of structs" {
+    const Item = struct { id: i32, name: []const u8 };
+    const a = [2]Item{ .{ .id = 1, .name = "one" }, .{ .id = 2, .name = "two" } };
+    const b = [2]Item{ .{ .id = 1, .name = "one" }, .{ .id = 2, .name = "two" } };
+    const c = [2]Item{ .{ .id = 1, .name = "one" }, .{ .id = 2, .name = "TWO" } };
+
+    try testing.expect(deepEqual([2]Item, a, b));
+    try testing.expect(!deepEqual([2]Item, a, c));
+}
+
+test "deepEqual struct with optional field" {
+    const Config = struct { name: []const u8, port: ?u16 };
+
+    try testing.expect(deepEqual(Config, .{ .name = "app", .port = 8080 }, .{ .name = "app", .port = 8080 }));
+    try testing.expect(deepEqual(Config, .{ .name = "app", .port = null }, .{ .name = "app", .port = null }));
+    try testing.expect(!deepEqual(Config, .{ .name = "app", .port = 8080 }, .{ .name = "app", .port = null }));
+    try testing.expect(!deepEqual(Config, .{ .name = "app", .port = 8080 }, .{ .name = "app", .port = 8081 }));
+}
+
+test "deepEqual struct with array field" {
+    const Data = struct { values: [3]i32 };
+
+    try testing.expect(deepEqual(Data, .{ .values = .{ 1, 2, 3 } }, .{ .values = .{ 1, 2, 3 } }));
+    try testing.expect(!deepEqual(Data, .{ .values = .{ 1, 2, 3 } }, .{ .values = .{ 1, 2, 4 } }));
+}

src/datastruct/main.zig

@@ -19,4 +19,6 @@ pub const SplitTree = split_tree.SplitTree;
 
 test {
     @import("std").testing.refAllDecls(@This());
+
+    _ = @import("comparison.zig");
 }