Cthulhu is no longer a fork. Now it is a screen reader written in Golang.

internal/ocr/model_test.go

@@ -0,0 +1,90 @@
+// Copyright (c) 2026 Storm Dragon
+// Authors: Storm Dragon, Angus Kola
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package ocr
+
+import (
+	"image"
+	"math"
+	"testing"
+)
+
+func TestTransformScreenRectangle(t *testing.T) {
+	transform := Transform{
+		ImageContent:     image.Rect(10, 20, 310, 221),
+		ScreenBounds:     image.Rect(-120, -50, -20, 50),
+		HasScreenMapping: true,
+	}
+	for _, test := range []struct {
+		name             string
+		bounds, expected image.Rectangle
+		valid            bool
+	}{
+		{"full", transform.ImageContent, transform.ScreenBounds, true},
+		{"independent axes", image.Rect(13, 22, 19, 26), image.Rect(-119, -50, -117, -47), true},
+		{"partial padding", image.Rect(0, 0, 13, 22), image.Rect(-120, -50, -119, -49), true},
+		{"only padding", image.Rect(0, 0, 10, 20), image.Rectangle{}, false},
+		{"empty", image.Rectangle{}, image.Rectangle{}, false},
+		{"beyond image", image.Rect(400, 400, 410, 410), image.Rectangle{}, false},
+	} {
+		t.Run(test.name, func(t *testing.T) {
+			got, valid := transform.ScreenRectangle(test.bounds)
+			if got != test.expected || valid != test.valid {
+				t.Fatalf("mapped %v, %v; want %v, %v", got, valid, test.expected, test.valid)
+			}
+		})
+	}
+	transform.HasScreenMapping = false
+	if _, valid := transform.ScreenRectangle(transform.ImageContent); valid {
+		t.Fatal("clipboard image acquired screen coordinates")
+	}
+	transform.HasScreenMapping = true
+	transform.ScreenBounds = image.Rect(math.MinInt32, 0, math.MinInt32+100, 100)
+	if _, valid := transform.ScreenRectangle(transform.ImageContent); valid {
+		t.Fatal("unknown native origin acquired coordinates")
+	}
+	transform.ScreenBounds = image.Rect(-math.MaxInt32, 0, math.MaxInt32, 100)
+	if _, valid := transform.ScreenRectangle(transform.ImageContent); valid {
+		t.Fatal("overflow-sized screen rectangle acquired coordinates")
+	}
+}
+
+func TestRuneOffsetsAndWordHitTesting(t *testing.T) {
+	result := Result{
+		Text: "é 中文\ne\u0301",
+		Words: []Word{
+			{Text: "é", Span: Span{0, 1}},
+			{Text: "中文", Span: Span{2, 4}},
+			{Text: "e\u0301", Span: Span{5, 7}},
+		},
+	}
+	for offset, want := range []int{0, 2, 3, 6, 9, 10, 11, 13} {
+		got, valid := result.ByteOffset(offset)
+		if !valid || got != want {
+			t.Fatalf("byte offset %d = %d, %v; want %d", offset, got, valid, want)
+		}
+	}
+	for _, offset := range []int{-1, 1, 4, 7, 8} {
+		if word, valid := result.WordAt(offset); valid {
+			t.Fatalf("separator/end offset %d chose %q", offset, word.Text)
+		}
+	}
+	for _, offset := range []int{0, 2, 3, 5, 6} {
+		if _, valid := result.WordAt(offset); !valid {
+			t.Fatalf("word offset %d missing", offset)
+		}
+	}
+	for _, offset := range []int{-1, 8} {
+		if _, valid := result.ByteOffset(offset); valid {
+			t.Fatalf("invalid rune offset %d accepted", offset)
+		}
+	}
+	if offset, valid := (Result{}).ByteOffset(0); offset != 0 || !valid {
+		t.Fatal("empty document lost its end position")
+	}
+	phrase := Result{Text: "a b", Words: []Word{{Text: "a b", Span: Span{0, 3}}}}
+	if _, valid := phrase.WordAt(1); valid {
+		t.Fatal("whitespace inside an engine word acquired an activation target")
+	}
+}