github.com/apernet/quic-go@v0.43.1-0.20240515053213-5e9e635fd9f0/internal/utils/byteoder_big_endian_test.go (about)

     1  package utils
     2  
     3  import (
     4  	"bytes"
     5  	"io"
     6  
     7  	. "github.com/onsi/ginkgo/v2"
     8  	. "github.com/onsi/gomega"
     9  )
    10  
    11  var _ = Describe("Big Endian encoding / decoding", func() {
    12  	Context("converting", func() {
    13  		It("Uint16", func() {
    14  			b := []byte{0x13, 0x37}
    15  			Expect(BigEndian.Uint16(b)).To(Equal(uint16(0x1337)))
    16  		})
    17  
    18  		It("Uint24", func() {
    19  			b := []byte{0x13, 0x99, 0x37}
    20  			Expect(BigEndian.Uint24(b)).To(Equal(uint32(0x139937)))
    21  		})
    22  
    23  		It("Uint32", func() {
    24  			b := []byte{0xde, 0xad, 0xbe, 0xef}
    25  			Expect(BigEndian.Uint32(b)).To(Equal(uint32(0xdeadbeef)))
    26  		})
    27  	})
    28  
    29  	Context("ReadUint16", func() {
    30  		It("reads a big endian", func() {
    31  			b := []byte{0x13, 0xEF}
    32  			val, err := BigEndian.ReadUint16(bytes.NewReader(b))
    33  			Expect(err).ToNot(HaveOccurred())
    34  			Expect(val).To(Equal(uint16(0x13EF)))
    35  		})
    36  
    37  		It("throws an error if less than 2 bytes are passed", func() {
    38  			b := []byte{0x13, 0xEF}
    39  			for i := 0; i < len(b); i++ {
    40  				_, err := BigEndian.ReadUint16(bytes.NewReader(b[:i]))
    41  				Expect(err).To(MatchError(io.EOF))
    42  			}
    43  		})
    44  	})
    45  
    46  	Context("ReadUint24", func() {
    47  		It("reads a big endian", func() {
    48  			b := []byte{0x13, 0xbe, 0xef}
    49  			val, err := BigEndian.ReadUint24(bytes.NewReader(b))
    50  			Expect(err).ToNot(HaveOccurred())
    51  			Expect(val).To(Equal(uint32(0x13beef)))
    52  		})
    53  
    54  		It("throws an error if less than 3 bytes are passed", func() {
    55  			b := []byte{0x13, 0xbe, 0xef}
    56  			for i := 0; i < len(b); i++ {
    57  				_, err := BigEndian.ReadUint24(bytes.NewReader(b[:i]))
    58  				Expect(err).To(MatchError(io.EOF))
    59  			}
    60  		})
    61  	})
    62  
    63  	Context("ReadUint32", func() {
    64  		It("reads a big endian", func() {
    65  			b := []byte{0x12, 0x35, 0xAB, 0xFF}
    66  			val, err := BigEndian.ReadUint32(bytes.NewReader(b))
    67  			Expect(err).ToNot(HaveOccurred())
    68  			Expect(val).To(Equal(uint32(0x1235ABFF)))
    69  		})
    70  
    71  		It("throws an error if less than 4 bytes are passed", func() {
    72  			b := []byte{0x12, 0x35, 0xAB, 0xFF}
    73  			for i := 0; i < len(b); i++ {
    74  				_, err := BigEndian.ReadUint32(bytes.NewReader(b[:i]))
    75  				Expect(err).To(MatchError(io.EOF))
    76  			}
    77  		})
    78  	})
    79  
    80  	Context("WriteUint16", func() {
    81  		It("outputs 2 bytes", func() {
    82  			b := &bytes.Buffer{}
    83  			BigEndian.WriteUint16(b, uint16(1))
    84  			Expect(b.Len()).To(Equal(2))
    85  		})
    86  
    87  		It("outputs a big endian", func() {
    88  			num := uint16(0xFF11)
    89  			b := &bytes.Buffer{}
    90  			BigEndian.WriteUint16(b, num)
    91  			Expect(b.Bytes()).To(Equal([]byte{0xFF, 0x11}))
    92  		})
    93  	})
    94  
    95  	Context("WriteUint24", func() {
    96  		It("outputs 3 bytes", func() {
    97  			b := &bytes.Buffer{}
    98  			BigEndian.WriteUint24(b, uint32(1))
    99  			Expect(b.Len()).To(Equal(3))
   100  		})
   101  
   102  		It("outputs a big endian", func() {
   103  			num := uint32(0xff11aa)
   104  			b := &bytes.Buffer{}
   105  			BigEndian.WriteUint24(b, num)
   106  			Expect(b.Bytes()).To(Equal([]byte{0xff, 0x11, 0xaa}))
   107  		})
   108  	})
   109  
   110  	Context("WriteUint32", func() {
   111  		It("outputs 4 bytes", func() {
   112  			b := &bytes.Buffer{}
   113  			BigEndian.WriteUint32(b, uint32(1))
   114  			Expect(b.Len()).To(Equal(4))
   115  		})
   116  
   117  		It("outputs a big endian", func() {
   118  			num := uint32(0xEFAC3512)
   119  			b := &bytes.Buffer{}
   120  			BigEndian.WriteUint32(b, num)
   121  			Expect(b.Bytes()).To(Equal([]byte{0xEF, 0xAC, 0x35, 0x12}))
   122  		})
   123  	})
   124  })