From a2dc3abcc25e323d6bea863fb906620e56811638 Mon Sep 17 00:00:00 2001
From: Eldar Shahmaliyev <shahmal1yevv@proton.me>
Date: Wed, 8 Jan 2025 20:18:36 +0400
Subject: [PATCH 1/5] (wip|[skip ci]): Add initial implementation for
 TextString encoding and tests

- Implement `TextString` class with an `encode` method for CBOR text string encoding based on the length.
- Placeholder added for the `decode` method (not yet implemented).
- Create `TextStringTest` to validate encoding functionality with various test cases.
- Include a data provider for encoding tests, covering short and long strings.

Note: Decoding functionality is still pending implementation.
---
 src/CBOR/MajorTypes/TextString.php            | 39 +++++++++++++
 tests/Unit/CBOR/MajorTypes/TextStringTest.php | 57 +++++++++++++++++++
 2 files changed, 96 insertions(+)
 create mode 100644 src/CBOR/MajorTypes/TextString.php
 create mode 100644 tests/Unit/CBOR/MajorTypes/TextStringTest.php

diff --git a/src/CBOR/MajorTypes/TextString.php b/src/CBOR/MajorTypes/TextString.php
new file mode 100644
index 0000000..788b826
--- /dev/null
+++ b/src/CBOR/MajorTypes/TextString.php
@@ -0,0 +1,39 @@
+<?php declare(strict_types = 1);
+
+/**
+ * This file is part of the ATProto Core package.
+ *
+ * (c) Core Branch
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+namespace ATProto\Core\CBOR\MajorTypes;
+
+class TextString
+{
+    public static function encode(string $input): string
+    {
+        $length = strlen($input);
+
+        if ($length <= 23) {
+            $header = chr((0x03 << 5) | $length);
+        } elseif ($length <= 0xFF) {
+            $header = chr((0x03 << 5) | 24) . chr($length);
+        } elseif ($length <= 0xFFFF) {
+            $header = chr((0x03 << 5) | 25) . pack('n', $length);
+        } elseif ($length <= 0xFFFFFFFF) {
+            $header = chr((0x03 << 5) | 26) . pack('N', $length);
+        } else {
+            $header = chr((0x03 << 5) | 27) . pack('J', $length);
+        }
+
+        return $header . $input;
+    }
+
+    public static function decode(string $input): string
+    {
+        // TODO
+    }
+}
\ No newline at end of file
diff --git a/tests/Unit/CBOR/MajorTypes/TextStringTest.php b/tests/Unit/CBOR/MajorTypes/TextStringTest.php
new file mode 100644
index 0000000..583983c
--- /dev/null
+++ b/tests/Unit/CBOR/MajorTypes/TextStringTest.php
@@ -0,0 +1,57 @@
+<?php declare(strict_types = 1);
+
+/**
+ * This file is part of the ATProto Core package.
+ *
+ * (c) Core Branch
+ *
+ * This source code is licensed under the MIT license found in the
+ * LICENSE file in the root directory of this source tree.
+ */
+
+namespace Tests\Unit\CBOR\MajorTypes;
+
+use ATProto\Core\CBOR\MajorTypes\TextString;
+use PHPUnit\Framework\Attributes\DataProvider;
+use PHPUnit\Framework\TestCase;
+
+class TextStringTest extends TestCase
+{
+    #[DataProvider('provideCases')]
+    public function testItCanEncodeCorrectly(string $case, string $header): void
+    {
+        $actual = bin2hex(TextString::encode($case));
+        $expected = bin2hex($header . $case);
+
+        $this->assertSame($expected, $actual);
+    }
+
+    #[DataProvider('provideCases')]
+    public function testItCanDecodeCorrectly(string $case, string $header): void
+    {
+        $target = $header . $case;
+
+        $actual = TextString::decode($target);
+        $expected = $case;
+
+        $this->assertSame($expected, $actual);
+    }
+
+    public static function provideCases(): array
+    {
+        return [
+            ["f", "\x61"],
+            ["fo", "\x62"],
+            ["foo", "\x63"],
+            ["foob", "\x64"],
+            ["fooba", "\x65"],
+            ["foobar", "\x66"],
+            [
+                "This is a longer string. This is a longer string. This is a longer string. This is a longer string. 
+                This is a longer string. This is a longer string. This is a longer string. This is a longer string. 
+                This is a longer string. This is a longer string. This is a longer string. This is a longer string.",
+                "\x79\x01\x4D"
+            ]
+        ];
+    }
+}

From 3957912b822a620a6140eada29413a11d5f1a302 Mon Sep 17 00:00:00 2001
From: Eldar Shahmaliyev <shahmal1yevv@proton.me>
Date: Wed, 8 Jan 2025 20:20:46 +0400
Subject: [PATCH 2/5] (wip|[skip ci]): Integrate TextString encoding into CBOR
 class

- Add support for encoding string data using the `TextString` class within the `CBOR::encode` method.
- Update the CBOR class to handle the `string` type by delegating encoding to `TextString::encode`.
- Keep the `decode` method as a placeholder for future implementation.
---
 src/CBOR/CBOR.php | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/src/CBOR/CBOR.php b/src/CBOR/CBOR.php
index 5c0224b..a2efb26 100644
--- a/src/CBOR/CBOR.php
+++ b/src/CBOR/CBOR.php
@@ -11,6 +11,7 @@
 
 namespace ATProto\Core\CBOR;
 
+use ATProto\Core\CBOR\MajorTypes\TextString;
 use ATProto\Core\CBOR\MajorTypes\UnsignedInteger;
 
 class CBOR
@@ -21,6 +22,9 @@ public static function encode(string|int|array $data): string
             case 'integer':
                 return UnsignedInteger::encode($data);
             break;
+            case 'string':
+                return TextString::encode($data);
+            break;
         }
 
         throw new \ValueError("Unsupported type: " . gettype($data));
@@ -28,6 +32,6 @@ public static function encode(string|int|array $data): string
 
     public static function decode(string $data): int
     {
-        return UnsignedInteger::decode((string) $data);
+        // TODO
     }
 }

From 28ca64da2f89539e8c054bbfc889faaaf95cb89d Mon Sep 17 00:00:00 2001
From: Eldar Shahmaliyev <shahmal1yevv@proton.me>
Date: Thu, 9 Jan 2025 16:56:45 +0400
Subject: [PATCH 3/5] feat(CBOR): Implement decode method for TextString and
 improve test suite

---
 src/CBOR/MajorTypes/TextString.php            | 38 ++++++++++++++-
 tests/Unit/CBOR/MajorTypes/TextStringTest.php | 46 +++++++++++++++----
 2 files changed, 72 insertions(+), 12 deletions(-)

diff --git a/src/CBOR/MajorTypes/TextString.php b/src/CBOR/MajorTypes/TextString.php
index 788b826..d155752 100644
--- a/src/CBOR/MajorTypes/TextString.php
+++ b/src/CBOR/MajorTypes/TextString.php
@@ -34,6 +34,40 @@ public static function encode(string $input): string
 
     public static function decode(string $input): string
     {
-        // TODO
+        $initialByte = ord($input[0]);
+        $majorType = ($initialByte >> 5) & 0x07;
+
+        if ($majorType !== 0x03) {
+            throw new \ValueError('Invalid CBOR TextString major type.');
+        }
+
+        $additionalInfo = $initialByte & 0x1F;
+        $offset = 1;
+
+        if ($additionalInfo <= 23) {
+            $length = $additionalInfo;
+        } elseif ($additionalInfo === 24) {
+            $length = ord($input[$offset]);
+            $offset += 1;
+        } elseif ($additionalInfo === 25) {
+            $length = unpack('n', substr($input, $offset, 2))[1];
+            $offset += 2;
+        } elseif ($additionalInfo === 26) {
+            $length = unpack('N', substr($input, $offset, 4))[1];
+            $offset += 4;
+        } elseif ($additionalInfo === 27) {
+            $length = unpack('J', substr($input, $offset, 8))[1];
+            $offset += 8;
+        } else {
+            throw new \ValueError('Invalid CBOR TextString length information.');
+        }
+
+        $text = substr($input, $offset, $length);
+
+        if (strlen($text) !== $length) {
+            throw new \ValueError('Invalid CBOR TextString length mismatch.');
+        }
+
+        return $text;
     }
-}
\ No newline at end of file
+}
diff --git a/tests/Unit/CBOR/MajorTypes/TextStringTest.php b/tests/Unit/CBOR/MajorTypes/TextStringTest.php
index 583983c..950b643 100644
--- a/tests/Unit/CBOR/MajorTypes/TextStringTest.php
+++ b/tests/Unit/CBOR/MajorTypes/TextStringTest.php
@@ -17,27 +17,27 @@
 
 class TextStringTest extends TestCase
 {
-    #[DataProvider('provideCases')]
-    public function testItCanEncodeCorrectly(string $case, string $header): void
+    #[DataProvider('provideValidCases')]
+    public function testEncodeProducesCorrectCBORRepresentation(string $input, string $expectedHeader): void
     {
-        $actual = bin2hex(TextString::encode($case));
-        $expected = bin2hex($header . $case);
+        $actual = bin2hex(TextString::encode($input));
+        $expected = bin2hex($expectedHeader . $input);
 
         $this->assertSame($expected, $actual);
     }
 
-    #[DataProvider('provideCases')]
-    public function testItCanDecodeCorrectly(string $case, string $header): void
+    #[DataProvider('provideValidCases')]
+    public function testDecodeExtractsOriginalStringFromCBORRepresentation(string $input, string $header): void
     {
-        $target = $header . $case;
+        $encoded = $header . $input;
 
-        $actual = TextString::decode($target);
-        $expected = $case;
+        $actual = TextString::decode($encoded);
+        $expected = $input;
 
         $this->assertSame($expected, $actual);
     }
 
-    public static function provideCases(): array
+    public static function provideValidCases(): array
     {
         return [
             ["f", "\x61"],
@@ -54,4 +54,30 @@ public static function provideCases(): array
             ]
         ];
     }
+
+    public function testDecodeThrowsExceptionForInvalidMajorType(): void
+    {
+        $this->expectException(\ValueError::class);
+        $this->expectExceptionMessage("Invalid CBOR TextString major type.");
+
+        TextString::decode("\x0C");
+    }
+
+    public function testDecodeThrowsExceptionForLengthMismatch(): void
+    {
+        $this->expectException(\ValueError::class);
+        $this->expectExceptionMessage("Invalid CBOR TextString length mismatch.");
+
+        // Encoded length is 5, but actual length is 4
+        TextString::decode("\x65\x66\x6F\x6F\x62");
+    }
+
+    public function testDecodeThrowsExceptionForInvalidAdditionalInformation(): void
+    {
+        $this->expectException(\ValueError::class);
+        $this->expectExceptionMessage("Invalid CBOR TextString length information.");
+
+        // Additional info 28 is invalid for text strings
+        TextString::decode("\x7C\x01");
+    }
 }

From 81c230bc6d6efd8ae277e7514f3f576fb51861e0 Mon Sep 17 00:00:00 2001
From: Eldar Shahmaliyev <shahmal1yevv@proton.me>
Date: Thu, 9 Jan 2025 18:00:16 +0400
Subject: [PATCH 4/5] feat(CBOR): Add decode support for TextString and
 UnsignedInteger with validation

- Implemented `decode` method in `CBOR` class to support both `TextString` and `UnsignedInteger` types.
- Added `validate` method to `TextString` and `UnsignedInteger` classes for type-specific validation.
- Updated `decode` methods in `TextString` and `UnsignedInteger` to use their respective `validate` methods.
- Enhanced `CBORTest` to include tests for decoding mixed types (`TextString` and `UnsignedInteger`).
- Fixed and refactored exception messages for better consistency and readability in `UnsignedInteger`.
---
 src/CBOR/CBOR.php                                 | 12 ++++++++++--
 src/CBOR/MajorTypes/TextString.php                | 12 +++++++-----
 src/CBOR/MajorTypes/UnsignedInteger.php           | 15 +++++++++------
 tests/Unit/CBOR/CBORTest.php                      |  8 ++++----
 .../Unit/CBOR/MajorTypes/UnsignedIntegerTest.php  |  2 +-
 5 files changed, 31 insertions(+), 18 deletions(-)

diff --git a/src/CBOR/CBOR.php b/src/CBOR/CBOR.php
index a2efb26..c83c76a 100644
--- a/src/CBOR/CBOR.php
+++ b/src/CBOR/CBOR.php
@@ -30,8 +30,16 @@ public static function encode(string|int|array $data): string
         throw new \ValueError("Unsupported type: " . gettype($data));
     }
 
-    public static function decode(string $data): int
+    public static function decode(string $data): int|string
     {
-        // TODO
+        if (TextString::validate($data)) {
+            return TextString::decode($data);
+        }
+
+        if (UnsignedInteger::validate($data)) {
+            return UnsignedInteger::decode($data);
+        }
+
+        throw new \ValueError("Unsupported type");
     }
 }
diff --git a/src/CBOR/MajorTypes/TextString.php b/src/CBOR/MajorTypes/TextString.php
index d155752..69fbdd8 100644
--- a/src/CBOR/MajorTypes/TextString.php
+++ b/src/CBOR/MajorTypes/TextString.php
@@ -34,14 +34,11 @@ public static function encode(string $input): string
 
     public static function decode(string $input): string
     {
-        $initialByte = ord($input[0]);
-        $majorType = ($initialByte >> 5) & 0x07;
-
-        if ($majorType !== 0x03) {
+        if (! self::validate($input)) {
             throw new \ValueError('Invalid CBOR TextString major type.');
         }
 
-        $additionalInfo = $initialByte & 0x1F;
+        $additionalInfo = ord($input[0]) & 0x1F;
         $offset = 1;
 
         if ($additionalInfo <= 23) {
@@ -70,4 +67,9 @@ public static function decode(string $input): string
 
         return $text;
     }
+
+    public static function validate(string $input): bool
+    {
+        return ((ord($input[0]) >> 5) & 0x07) === 0x03;
+    }
 }
diff --git a/src/CBOR/MajorTypes/UnsignedInteger.php b/src/CBOR/MajorTypes/UnsignedInteger.php
index aef69b7..e8a712a 100644
--- a/src/CBOR/MajorTypes/UnsignedInteger.php
+++ b/src/CBOR/MajorTypes/UnsignedInteger.php
@@ -17,14 +17,12 @@ class UnsignedInteger
 {
     public static function decode(string $data): int
     {
-        $firstByte = ord($data[0]);
-        $majorType = ($firstByte >> 5) & 0x07;
-        $additionalInfo = $firstByte & 0x1F;
-
-        if ($majorType !== 0) {
-            throw new ValueError("Invalid major type for unsigned integer: $majorType");
+        if (! self::validate($data)) {
+            throw new ValueError("Invalid major type for unsigned integer.");
         }
 
+        $additionalInfo = ord($data[0]) & 0x1F;
+
         if ($additionalInfo <= 23) {
             $value = $additionalInfo;
         } elseif ($additionalInfo === 24) {
@@ -73,4 +71,9 @@ public static function encode(int $value): string
 
         return $prefixedPack('J', "\x1B");
     }
+
+    public static function validate(string $input): bool
+    {
+        return ((ord($input[0]) >> 5) & 0x07) === 0x00;
+    }
 }
diff --git a/tests/Unit/CBOR/CBORTest.php b/tests/Unit/CBOR/CBORTest.php
index 2e21ea6..0158a63 100644
--- a/tests/Unit/CBOR/CBORTest.php
+++ b/tests/Unit/CBOR/CBORTest.php
@@ -18,14 +18,14 @@
 class CBORTest extends TestCase
 {
     #[DataProvider('validCases')]
-    public function testEncode(int $data, string $expected): void
+    public function testEncode(int|string $data, string $expected): void
     {
         $encoded = CBOR::encode($data);
         $this->assertSame($expected, $encoded);
     }
 
     #[DataProvider('validCases')]
-    public function testDecode(int $expected, string $data): void
+    public function testDecode(int|string $expected, string $data): void
     {
         $actual = CBOR::decode($data);
 
@@ -42,8 +42,8 @@ public static function validCases(): array
             [1, hex2bin('01')], // 1 encoded as CBOR unsigned integer
             [10, hex2bin('0a')], // 10 encoded as CBOR unsigned integer
 
-//            // String test cases
-//            [['hello'], hex2bin('6568656c6c6f')], // "hello" encoded as CBOR text string
+            // String test cases
+            ['hello', hex2bin('6568656C6C6F')], // "hello" encoded as CBOR text string
 //
 //            // Boolean test cases
 //            [[true], hex2bin('f5')], // true encoded as CBOR special type
diff --git a/tests/Unit/CBOR/MajorTypes/UnsignedIntegerTest.php b/tests/Unit/CBOR/MajorTypes/UnsignedIntegerTest.php
index cc41ff6..e725853 100644
--- a/tests/Unit/CBOR/MajorTypes/UnsignedIntegerTest.php
+++ b/tests/Unit/CBOR/MajorTypes/UnsignedIntegerTest.php
@@ -47,7 +47,7 @@ public function testEncodeThrowsAnExceptionForValueGreaterThanIntMax(): void
     public function testDecodeThrowsAnExceptionWhenPassedInvalidValue(string $case): void
     {
         $this->expectException(\ValueError::class);
-        $this->expectExceptionMessage("Invalid major type for unsigned integer: ");
+        $this->expectExceptionMessage("Invalid major type for unsigned integer.");
 
         UnsignedInteger::decode($case);
     }

From eea8a0305facdc50470933777fb9087bc2e29994 Mon Sep 17 00:00:00 2001
From: Eldar Shahmaliyev <shahmal1yevv@proton.me>
Date: Thu, 9 Jan 2025 18:27:52 +0400
Subject: [PATCH 5/5] test(CBOR): Improve test coverage for CBOR and TextString

---
 src/CBOR/CBOR.php                             |  2 +-
 tests/Unit/CBOR/CBORTest.php                  | 16 ++++++++++++++++
 tests/Unit/CBOR/MajorTypes/TextStringTest.php |  4 ++++
 3 files changed, 21 insertions(+), 1 deletion(-)

diff --git a/src/CBOR/CBOR.php b/src/CBOR/CBOR.php
index c83c76a..d1867ba 100644
--- a/src/CBOR/CBOR.php
+++ b/src/CBOR/CBOR.php
@@ -40,6 +40,6 @@ public static function decode(string $data): int|string
             return UnsignedInteger::decode($data);
         }
 
-        throw new \ValueError("Unsupported type");
+        throw new \ValueError("Unsupported type.");
     }
 }
diff --git a/tests/Unit/CBOR/CBORTest.php b/tests/Unit/CBOR/CBORTest.php
index 0158a63..d1adbf9 100644
--- a/tests/Unit/CBOR/CBORTest.php
+++ b/tests/Unit/CBOR/CBORTest.php
@@ -32,6 +32,22 @@ public function testDecode(int|string $expected, string $data): void
         $this->assertSame($expected, $actual);
     }
 
+    public function testCBORDecodeThrowsExceptionWhenPassedUnsupportedType(): void
+    {
+        $this->expectException(\ValueError::class);
+        $this->expectExceptionMessage('Unsupported type.');
+
+        CBOR::decode("\x80"); // CBOR array
+    }
+
+    public function testCBOREncodeThrowsExceptionWhenPassedUnsupportedType(): void
+    {
+        $this->expectException(\ValueError::class);
+        $this->expectExceptionMessage('Unsupported type: array');
+
+        CBOR::encode(array());
+    }
+
     /**
      * @return array[]
      */
diff --git a/tests/Unit/CBOR/MajorTypes/TextStringTest.php b/tests/Unit/CBOR/MajorTypes/TextStringTest.php
index 950b643..fb34fd9 100644
--- a/tests/Unit/CBOR/MajorTypes/TextStringTest.php
+++ b/tests/Unit/CBOR/MajorTypes/TextStringTest.php
@@ -46,6 +46,10 @@ public static function provideValidCases(): array
             ["foob", "\x64"],
             ["fooba", "\x65"],
             ["foobar", "\x66"],
+            [
+                "This is a longer string. This is a longer string. This is a longer string. This is a longer string.",
+                "\x78\x63"
+            ],
             [
                 "This is a longer string. This is a longer string. This is a longer string. This is a longer string. 
                 This is a longer string. This is a longer string. This is a longer string. This is a longer string.