v0.4.1

Co-authored-by: Rod Vagg <rod@vagg.org>

.github/workflows/go-check.yml

@@ -8,26 +8,20 @@ jobs:
   unit:
     runs-on: ubuntu-latest
     name: All
-    env:
-      RUNGOGENERATE: false
     steps:
       - uses: actions/checkout@v3
         with:
           submodules: recursive
+      - id: config
+        uses: protocol/.github/.github/actions/read-config@master
       - uses: actions/setup-go@v3
         with:
-          go-version: "1.19.x"
+          go-version: 1.20.x
       - name: Run repo-specific setup
         uses: ./.github/actions/go-check-setup
         if: hashFiles('./.github/actions/go-check-setup') != ''
-      - name: Read config
-        if: hashFiles('./.github/workflows/go-check-config.json') != ''
-        run: |
-          if jq -re .gogenerate ./.github/workflows/go-check-config.json; then
-            echo "RUNGOGENERATE=true" >> $GITHUB_ENV
-          fi
       - name: Install staticcheck
-        run: go install honnef.co/go/tools/cmd/staticcheck@376210a89477dedbe6fdc4484b233998650d7b3c # 2022.1.3 (v0.3.3)
+        run: go install honnef.co/go/tools/cmd/staticcheck@4970552d932f48b71485287748246cf3237cebdf # 2023.1 (v0.4.0)
       - name: Check that go.mod is tidy
         uses: protocol/multiple-go-modules@v1.2
         with:
@@ -39,7 +33,7 @@ jobs:
             fi
             git diff --exit-code -- go.sum go.mod
       - name: gofmt
-        if: ${{ success() || failure() }} # run this step even if the previous one failed
+        if: success() || failure() # run this step even if the previous one failed
         run: |
           out=$(gofmt -s -l .)
           if [[ -n "$out" ]]; then
@@ -47,12 +41,12 @@ jobs:
             exit 1
           fi
       - name: go vet
-        if: ${{ success() || failure() }} # run this step even if the previous one failed
+        if: success() || failure() # run this step even if the previous one failed
         uses: protocol/multiple-go-modules@v1.2
         with:
           run: go vet ./...
       - name: staticcheck
-        if: ${{ success() || failure() }} # run this step even if the previous one failed
+        if: success() || failure() # run this step even if the previous one failed
         uses: protocol/multiple-go-modules@v1.2
         with:
           run: |
@@ -60,11 +54,11 @@ jobs:
             staticcheck ./... | sed -e 's@\(.*\)\.go@./\1.go@g'
       - name: go generate
         uses: protocol/multiple-go-modules@v1.2
-        if: (success() || failure()) && env.RUNGOGENERATE == 'true'
+        if: (success() || failure()) && fromJSON(steps.config.outputs.json).gogenerate == true
         with:
           run: |
             git clean -fd # make sure there aren't untracked files / directories
-            go generate ./...
+            go generate -x ./...
             # check if go generate modified or added any files
             if ! $(git add . && git diff-index HEAD --exit-code --quiet); then
               echo "go generated caused changes to the repository:"

.github/workflows/go-test.yml

@@ -10,15 +10,17 @@ jobs:
       fail-fast: false
       matrix:
         os: [ "ubuntu", "windows", "macos" ]
-        go: [ "1.18.x", "1.19.x" ]
+        go: ["1.19.x","1.20.x"]
     env:
       COVERAGES: ""
-    runs-on: ${{ format('{0}-latest', matrix.os) }}
+    runs-on: ${{ fromJSON(vars[format('UCI_GO_TEST_RUNNER_{0}', matrix.os)] || format('"{0}-latest"', matrix.os)) }}
     name: ${{ matrix.os }} (go ${{ matrix.go }})
     steps:
       - uses: actions/checkout@v3
         with:
           submodules: recursive
+      - id: config
+        uses: protocol/.github/.github/actions/read-config@master
       - uses: actions/setup-go@v3
         with:
           go-version: ${{ matrix.go }}
@@ -27,7 +29,7 @@ jobs:
           go version
           go env
       - name: Use msys2 on windows
-        if: ${{ matrix.os == 'windows' }}
+        if: matrix.os == 'windows'
         shell: bash
         # The executable for msys2 is also called bash.cmd
         #   https://github.com/actions/virtual-environments/blob/main/images/win/Windows2019-Readme.md#shells
@@ -38,6 +40,7 @@ jobs:
         uses: ./.github/actions/go-test-setup
         if: hashFiles('./.github/actions/go-test-setup') != ''
       - name: Run tests
+        if: contains(fromJSON(steps.config.outputs.json).skipOSes, matrix.os) == false
         uses: protocol/multiple-go-modules@v1.2
         with:
           # Use -coverpkg=./..., so that we include cross-package coverage.
@@ -45,16 +48,21 @@ jobs:
           # this means ./B's coverage will be significantly higher than 0%.
           run: go test -v -shuffle=on -coverprofile=module-coverage.txt -coverpkg=./... ./...
       - name: Run tests (32 bit)
-        if: ${{ matrix.os != 'macos' }} # can't run 32 bit tests on OSX.
+        # can't run 32 bit tests on OSX.
+        if: matrix.os != 'macos' &&
+          fromJSON(steps.config.outputs.json).skip32bit != true &&
+          contains(fromJSON(steps.config.outputs.json).skipOSes, matrix.os) == false
         uses: protocol/multiple-go-modules@v1.2
         env:
           GOARCH: 386
         with:
           run: |
-            export "PATH=${{ env.PATH_386 }}:$PATH"
+            export "PATH=$PATH_386:$PATH"
             go test -v -shuffle=on ./...
       - name: Run tests with race detector
-        if: ${{ matrix.os == 'ubuntu' }} # speed things up. Windows and OSX VMs are slow
+        # speed things up. Windows and OSX VMs are slow
+        if: matrix.os == 'ubuntu' &&
+          contains(fromJSON(steps.config.outputs.json).skipOSes, matrix.os) == false
         uses: protocol/multiple-go-modules@v1.2
         with:
           run: go test -v -race ./...
@@ -62,7 +70,7 @@ jobs:
         shell: bash
         run: echo "COVERAGES=$(find . -type f -name 'module-coverage.txt' | tr -s '\n' ',' | sed 's/,$//')" >> $GITHUB_ENV
       - name: Upload coverage to Codecov
-        uses: codecov/codecov-action@81cd2dc8148241f03f5839d295e000b8f761e378 # v3.1.0
+        uses: codecov/codecov-action@d9f34f8cd5cb3b3eb79b3e4b5dae3a16df499a70 # v3.1.1
         with:
           files: '${{ env.COVERAGES }}'
           env_vars: OS=${{ matrix.os }}, GO=${{ matrix.go }}

.github/workflows/release-check.yml

@@ -3,9 +3,11 @@
 
 name: Release Checker
 on:
-  pull_request:
+  pull_request_target:
     paths: [ 'version.json' ]
 
 jobs:
   release-check:
     uses: protocol/.github/.github/workflows/release-check.yml@master
+    with:
+      go-version: 1.20.x

README.md

@@ -69,7 +69,7 @@ import (
 // Create a cid manually by specifying the 'prefix' parameters
 pref := cid.Prefix{
 	Version: 1,
-	Codec: mc.Raw,
+	Codec: uint64(mc.Raw),
 	MhType: mh.SHA2_256,
 	MhLength: -1, // default length
 }

cid.go

@@ -37,10 +37,32 @@ import (
 // UnsupportedVersionString just holds an error message
 const UnsupportedVersionString = "<unsupported cid version>"
 
+// ErrInvalidCid is an error that indicates that a CID is invalid.
+type ErrInvalidCid struct {
+	Err error
+}
+
+func (e ErrInvalidCid) Error() string {
+	return fmt.Sprintf("invalid cid: %s", e.Err)
+}
+
+func (e ErrInvalidCid) Unwrap() error {
+	return e.Err
+}
+
+func (e ErrInvalidCid) Is(err error) bool {
+	switch err.(type) {
+	case ErrInvalidCid, *ErrInvalidCid:
+		return true
+	default:
+		return false
+	}
+}
+
 var (
 	// ErrCidTooShort means that the cid passed to decode was not long
 	// enough to be a valid Cid
-	ErrCidTooShort = errors.New("cid too short")
+	ErrCidTooShort = ErrInvalidCid{errors.New("cid too short")}
 
 	// ErrInvalidEncoding means that selected encoding is not supported
 	// by this Cid version
@@ -90,10 +112,10 @@ func tryNewCidV0(mhash mh.Multihash) (Cid, error) {
 	// incorrectly detect it as CidV1 in the Version() method
 	dec, err := mh.Decode(mhash)
 	if err != nil {
-		return Undef, err
+		return Undef, ErrInvalidCid{err}
 	}
 	if dec.Code != mh.SHA2_256 || dec.Length != 32 {
-		return Undef, fmt.Errorf("invalid hash for cidv0 %d-%d", dec.Code, dec.Length)
+		return Undef, ErrInvalidCid{fmt.Errorf("invalid hash for cidv0 %d-%d", dec.Code, dec.Length)}
 	}
 	return Cid{string(mhash)}, nil
 }
@@ -177,7 +199,7 @@ func Parse(v interface{}) (Cid, error) {
 	case Cid:
 		return v2, nil
 	default:
-		return Undef, fmt.Errorf("can't parse %+v as Cid", v2)
+		return Undef, ErrInvalidCid{fmt.Errorf("can't parse %+v as Cid", v2)}
 	}
 }
 
@@ -210,7 +232,7 @@ func Decode(v string) (Cid, error) {
 	if len(v) == 46 && v[:2] == "Qm" {
 		hash, err := mh.FromB58String(v)
 		if err != nil {
-			return Undef, err
+			return Undef, ErrInvalidCid{err}
 		}
 
 		return tryNewCidV0(hash)
@@ -218,7 +240,7 @@ func Decode(v string) (Cid, error) {
 
 	_, data, err := mbase.Decode(v)
 	if err != nil {
-		return Undef, err
+		return Undef, ErrInvalidCid{err}
 	}
 
 	return Cast(data)
@@ -240,7 +262,7 @@ func ExtractEncoding(v string) (mbase.Encoding, error) {
 	// check encoding is valid
 	_, err := mbase.NewEncoder(encoding)
 	if err != nil {
-		return -1, err
+		return -1, ErrInvalidCid{err}
 	}
 
 	return encoding, nil
@@ -260,11 +282,11 @@ func ExtractEncoding(v string) (mbase.Encoding, error) {
 func Cast(data []byte) (Cid, error) {
 	nr, c, err := CidFromBytes(data)
 	if err != nil {
-		return Undef, err
+		return Undef, ErrInvalidCid{err}
 	}
 
 	if nr != len(data) {
-		return Undef, fmt.Errorf("trailing bytes in data buffer passed to cid Cast")
+		return Undef, ErrInvalidCid{fmt.Errorf("trailing bytes in data buffer passed to cid Cast")}
 	}
 
 	return c, nil
@@ -434,7 +456,7 @@ func (c Cid) Equals(o Cid) bool {
 // UnmarshalJSON parses the JSON representation of a Cid.
 func (c *Cid) UnmarshalJSON(b []byte) error {
 	if len(b) < 2 {
-		return fmt.Errorf("invalid cid json blob")
+		return ErrInvalidCid{fmt.Errorf("invalid cid json blob")}
 	}
 	obj := struct {
 		CidTarget string `json:"/"`
@@ -442,7 +464,7 @@ func (c *Cid) UnmarshalJSON(b []byte) error {
 	objptr := &obj
 	err := json.Unmarshal(b, &objptr)
 	if err != nil {
-		return err
+		return ErrInvalidCid{err}
 	}
 	if objptr == nil {
 		*c = Cid{}
@@ -450,12 +472,12 @@ func (c *Cid) UnmarshalJSON(b []byte) error {
 	}
 
 	if obj.CidTarget == "" {
-		return fmt.Errorf("cid was incorrectly formatted")
+		return ErrInvalidCid{fmt.Errorf("cid was incorrectly formatted")}
 	}
 
 	out, err := Decode(obj.CidTarget)
 	if err != nil {
-		return err
+		return ErrInvalidCid{err}
 	}
 
 	*c = out
@@ -542,12 +564,12 @@ func (p Prefix) Sum(data []byte) (Cid, error) {
 	if p.Version == 0 && (p.MhType != mh.SHA2_256 ||
 		(p.MhLength != 32 && p.MhLength != -1)) {
 
-		return Undef, fmt.Errorf("invalid v0 prefix")
+		return Undef, ErrInvalidCid{fmt.Errorf("invalid v0 prefix")}
 	}
 
 	hash, err := mh.Sum(data, p.MhType, length)
 	if err != nil {
-		return Undef, err
+		return Undef, ErrInvalidCid{err}
 	}
 
 	switch p.Version {
@@ -556,7 +578,7 @@ func (p Prefix) Sum(data []byte) (Cid, error) {
 	case 1:
 		return NewCidV1(p.Codec, hash), nil
 	default:
-		return Undef, fmt.Errorf("invalid cid version")
+		return Undef, ErrInvalidCid{fmt.Errorf("invalid cid version")}
 	}
 }
 
@@ -586,22 +608,22 @@ func PrefixFromBytes(buf []byte) (Prefix, error) {
 	r := bytes.NewReader(buf)
 	vers, err := varint.ReadUvarint(r)
 	if err != nil {
-		return Prefix{}, err
+		return Prefix{}, ErrInvalidCid{err}
 	}
 
 	codec, err := varint.ReadUvarint(r)
 	if err != nil {
-		return Prefix{}, err
+		return Prefix{}, ErrInvalidCid{err}
 	}
 
 	mhtype, err := varint.ReadUvarint(r)
 	if err != nil {
-		return Prefix{}, err
+		return Prefix{}, ErrInvalidCid{err}
 	}
 
 	mhlen, err := varint.ReadUvarint(r)
 	if err != nil {
-		return Prefix{}, err
+		return Prefix{}, ErrInvalidCid{err}
 	}
 
 	return Prefix{
@@ -615,12 +637,12 @@ func PrefixFromBytes(buf []byte) (Prefix, error) {
 func CidFromBytes(data []byte) (int, Cid, error) {
 	if len(data) > 2 && data[0] == mh.SHA2_256 && data[1] == 32 {
 		if len(data) < 34 {
-			return 0, Undef, fmt.Errorf("not enough bytes for cid v0")
+			return 0, Undef, ErrInvalidCid{fmt.Errorf("not enough bytes for cid v0")}
 		}
 
 		h, err := mh.Cast(data[:34])
 		if err != nil {
-			return 0, Undef, err
+			return 0, Undef, ErrInvalidCid{err}
 		}
 
 		return 34, Cid{string(h)}, nil
@@ -628,21 +650,21 @@ func CidFromBytes(data []byte) (int, Cid, error) {
 
 	vers, n, err := varint.FromUvarint(data)
 	if err != nil {
-		return 0, Undef, err
+		return 0, Undef, ErrInvalidCid{err}
 	}
 
 	if vers != 1 {
-		return 0, Undef, fmt.Errorf("expected 1 as the cid version number, got: %d", vers)
+		return 0, Undef, ErrInvalidCid{fmt.Errorf("expected 1 as the cid version number, got: %d", vers)}
 	}
 
 	_, cn, err := varint.FromUvarint(data[n:])
 	if err != nil {
-		return 0, Undef, err
+		return 0, Undef, ErrInvalidCid{err}
 	}
 
 	mhnr, _, err := mh.MHFromBytes(data[n+cn:])
 	if err != nil {
-		return 0, Undef, err
+		return 0, Undef, ErrInvalidCid{err}
 	}
 
 	l := n + cn + mhnr
@@ -695,6 +717,9 @@ func (r *bufByteReader) ReadByte() (byte, error) {
 // It's recommended to supply a reader that buffers and implements io.ByteReader,
 // as CidFromReader has to do many single-byte reads to decode varints.
 // If the argument only implements io.Reader, single-byte Read calls are used instead.
+//
+// If the Reader is found to yield zero bytes, an io.EOF error is returned directly, in all
+// other error cases, an ErrInvalidCid, wrapping the original error, is returned.
 func CidFromReader(r io.Reader) (int, Cid, error) {
 	// 64 bytes is enough for any CIDv0,
 	// and it's enough for most CIDv1s in practice.
@@ -705,32 +730,37 @@ func CidFromReader(r io.Reader) (int, Cid, error) {
 	// The varint package wants a io.ByteReader, so we must wrap our io.Reader.
 	vers, err := varint.ReadUvarint(br)
 	if err != nil {
-		return len(br.dst), Undef, err
+		if err == io.EOF {
+			// First-byte read in ReadUvarint errors with io.EOF, so reader has no data.
+			// Subsequent reads with an EOF will return io.ErrUnexpectedEOF and be wrapped here.
+			return 0, Undef, err
+		}
+		return len(br.dst), Undef, ErrInvalidCid{err}
 	}
 
 	// If we have a CIDv0, read the rest of the bytes and cast the buffer.
 	if vers == mh.SHA2_256 {
 		if n, err := io.ReadFull(r, br.dst[1:34]); err != nil {
-			return len(br.dst) + n, Undef, err
+			return len(br.dst) + n, Undef, ErrInvalidCid{err}
 		}
 
 		br.dst = br.dst[:34]
 		h, err := mh.Cast(br.dst)
 		if err != nil {
-			return len(br.dst), Undef, err
+			return len(br.dst), Undef, ErrInvalidCid{err}
 		}
 
 		return len(br.dst), Cid{string(h)}, nil
 	}
 
 	if vers != 1 {
-		return len(br.dst), Undef, fmt.Errorf("expected 1 as the cid version number, got: %d", vers)
+		return len(br.dst), Undef, ErrInvalidCid{fmt.Errorf("expected 1 as the cid version number, got: %d", vers)}
 	}
 
 	// CID block encoding multicodec.
 	_, err = varint.ReadUvarint(br)
 	if err != nil {
-		return len(br.dst), Undef, err
+		return len(br.dst), Undef, ErrInvalidCid{err}
 	}
 
 	// We could replace most of the code below with go-multihash's ReadMultihash.
@@ -741,19 +771,19 @@ func CidFromReader(r io.Reader) (int, Cid, error) {
 	// Multihash hash function code.
 	_, err = varint.ReadUvarint(br)
 	if err != nil {
-		return len(br.dst), Undef, err
+		return len(br.dst), Undef, ErrInvalidCid{err}
 	}
 
 	// Multihash digest length.
 	mhl, err := varint.ReadUvarint(br)
 	if err != nil {
-		return len(br.dst), Undef, err
+		return len(br.dst), Undef, ErrInvalidCid{err}
 	}
 
 	// Refuse to make large allocations to prevent OOMs due to bugs.
 	const maxDigestAlloc = 32 << 20 // 32MiB
 	if mhl > maxDigestAlloc {
-		return len(br.dst), Undef, fmt.Errorf("refusing to allocate %d bytes for a digest", mhl)
+		return len(br.dst), Undef, ErrInvalidCid{fmt.Errorf("refusing to allocate %d bytes for a digest", mhl)}
 	}
 
 	// Fine to convert mhl to int, given maxDigestAlloc.
@@ -772,7 +802,7 @@ func CidFromReader(r io.Reader) (int, Cid, error) {
 	if n, err := io.ReadFull(r, br.dst[prefixLength:cidLength]); err != nil {
 		// We can't use len(br.dst) here,
 		// as we've only read n bytes past prefixLength.
-		return prefixLength + n, Undef, err
+		return prefixLength + n, Undef, ErrInvalidCid{err}
 	}
 
 	// This simply ensures the multihash is valid.
@@ -780,7 +810,7 @@ func CidFromReader(r io.Reader) (int, Cid, error) {
 	// for now, it helps ensure consistency with CidFromBytes.
 	_, _, err = mh.MHFromBytes(br.dst[mhStart:])
 	if err != nil {
-		return len(br.dst), Undef, err
+		return len(br.dst), Undef, ErrInvalidCid{err}
 	}
 
 	return len(br.dst), Cid{string(br.dst)}, nil

cid_test.go

@@ -2,7 +2,9 @@ package cid
 
 import (
 	"bytes"
+	crand "crypto/rand"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"io"
 	"math/rand"
@@ -161,6 +163,9 @@ func TestBasesMarshaling(t *testing.T) {
 	if err == nil {
 		t.Fatal("expected too-short error from ExtractEncoding")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("expected error to be ErrInvalidCid")
+	}
 	if ee != -1 {
 		t.Fatal("expected -1 from too-short ExtractEncoding")
 	}
@@ -226,6 +231,9 @@ func TestEmptyString(t *testing.T) {
 	if err == nil {
 		t.Fatal("shouldnt be able to parse an empty cid")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("error must be ErrInvalidCid")
+	}
 }
 
 func TestV0Handling(t *testing.T) {
@@ -281,6 +289,9 @@ func TestV0ErrorCases(t *testing.T) {
 	if err == nil {
 		t.Fatal("should have failed to decode that ref")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("error must be ErrInvalidCid")
+	}
 }
 
 func TestNewPrefixV1(t *testing.T) {
@@ -371,6 +382,9 @@ func TestInvalidV0Prefix(t *testing.T) {
 		if err == nil {
 			t.Fatalf("should error (index %d)", i)
 		}
+		if !errors.Is(err, ErrInvalidCid{}) {
+			t.Fatal("expected error to be ErrInvalidCid")
+		}
 	}
 }
 
@@ -380,6 +394,9 @@ func TestBadPrefix(t *testing.T) {
 	if err == nil {
 		t.Fatalf("expected error on v3 prefix Sum")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("expected error to be ErrInvalidCid")
+	}
 }
 
 func TestPrefixRoundtrip(t *testing.T) {
@@ -416,18 +433,30 @@ func TestBadPrefixFromBytes(t *testing.T) {
 	if err == nil {
 		t.Fatal("expected error for bad byte 0")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("expected error to be ErrInvalidCid")
+	}
 	_, err = PrefixFromBytes([]byte{0x01, 0x80})
 	if err == nil {
 		t.Fatal("expected error for bad byte 1")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("expected error to be ErrInvalidCid")
+	}
 	_, err = PrefixFromBytes([]byte{0x01, 0x01, 0x80})
 	if err == nil {
 		t.Fatal("expected error for bad byte 2")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("expected error to be ErrInvalidCid")
+	}
 	_, err = PrefixFromBytes([]byte{0x01, 0x01, 0x01, 0x80})
 	if err == nil {
 		t.Fatal("expected error for bad byte 3")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("expected error to be ErrInvalidCid")
+	}
 }
 
 func Test16BytesVarint(t *testing.T) {
@@ -441,7 +470,7 @@ func TestFuzzCid(t *testing.T) {
 	buf := make([]byte, 128)
 	for i := 0; i < 200; i++ {
 		s := rand.Intn(128)
-		rand.Read(buf[:s])
+		crand.Read(buf[:s])
 		_, _ = Cast(buf[:s])
 	}
 }
@@ -454,6 +483,9 @@ func TestParse(t *testing.T) {
 	if !strings.Contains(err.Error(), "can't parse 123 as Cid") {
 		t.Fatalf("expected int error, got %s", err.Error())
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatalf("expected ErrInvalidCid, got %s", err.Error())
+	}
 
 	theHash := "QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zR1n"
 	h, err := mh.FromB58String(theHash)
@@ -571,17 +603,29 @@ func TestJsonRoundTrip(t *testing.T) {
 		t.Fatal("cids not equal for Cid")
 	}
 
-	if err = actual2.UnmarshalJSON([]byte("1")); err == nil {
+	err = actual2.UnmarshalJSON([]byte("1"))
+	if err == nil {
 		t.Fatal("expected error for too-short JSON")
 	}
-
-	if err = actual2.UnmarshalJSON([]byte(`{"nope":"nope"}`)); err == nil {
-		t.Fatal("expected error for bad CID JSON")
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("expected error to be ErrInvalidCid")
 	}
 
-	if err = actual2.UnmarshalJSON([]byte(`bad "" json!`)); err == nil {
+	err = actual2.UnmarshalJSON([]byte(`{"nope":"nope"}`))
+	if err == nil {
+		t.Fatal("expected error for bad CID JSON")
+	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("expected error to be ErrInvalidCid")
+	}
+
+	err = actual2.UnmarshalJSON([]byte(`bad "" json!`))
+	if err == nil {
 		t.Fatal("expected error for bad JSON")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("expected error to be ErrInvalidCid")
+	}
 
 	var actual3 Cid
 	enc, err = actual3.MarshalJSON()
@@ -739,6 +783,30 @@ func TestBadCidInput(t *testing.T) {
 	}
 }
 
+func TestFromReaderNoData(t *testing.T) {
+	// Reading no data from io.Reader should return io.EOF, not ErrInvalidCid.
+	n, cid, err := CidFromReader(bytes.NewReader(nil))
+	if err != io.EOF {
+		t.Fatal("Expected io.EOF error")
+	}
+	if cid != Undef {
+		t.Fatal("Expected Undef CID")
+	}
+	if n != 0 {
+		t.Fatal("Expected 0 data")
+	}
+
+	// Read byte indicatiing more data to and check error is ErrInvalidCid.
+	_, _, err = CidFromReader(bytes.NewReader([]byte{0x80}))
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("Expected ErrInvalidCid error")
+	}
+	// Check for expected wrapped error.
+	if !errors.Is(err, io.ErrUnexpectedEOF) {
+		t.Fatal("Expected error", io.ErrUnexpectedEOF)
+	}
+}
+
 func TestBadParse(t *testing.T) {
 	hash, err := mh.Sum([]byte("foobar"), mh.SHA3_256, -1)
 	if err != nil {
@@ -748,6 +816,9 @@ func TestBadParse(t *testing.T) {
 	if err == nil {
 		t.Fatal("expected to fail to parse an invalid CIDv1 CID")
 	}
+	if !errors.Is(err, ErrInvalidCid{}) {
+		t.Fatal("error must be ErrInvalidCid")
+	}
 }
 
 func TestLoggable(t *testing.T) {
@@ -762,3 +833,80 @@ func TestLoggable(t *testing.T) {
 		t.Fatalf("did not get expected loggable form (got %v)", actual)
 	}
 }
+
+func TestErrInvalidCidIs(t *testing.T) {
+	for i, test := range []struct {
+		err    error
+		target error
+	}{
+		{&ErrInvalidCid{}, ErrInvalidCid{}},
+		{ErrInvalidCid{}, &ErrInvalidCid{}},
+		{ErrInvalidCid{}, ErrInvalidCid{}},
+		{&ErrInvalidCid{}, &ErrInvalidCid{}},
+	} {
+		if !errors.Is(test.err, test.target) {
+			t.Fatalf("expected error to be ErrInvalidCid, case %d", i)
+		}
+	}
+}
+
+func TestErrInvalidCid(t *testing.T) {
+	run := func(err error) {
+		if err == nil {
+			t.Fatal("expected error")
+		}
+
+		if !strings.HasPrefix(err.Error(), "invalid cid: ") {
+			t.Fatal(`expected error message to contain "invalid cid: "`)
+		}
+
+		is := errors.Is(err, ErrInvalidCid{})
+		if !is {
+			t.Fatal("expected error to be ErrInvalidCid")
+		}
+
+		if !errors.Is(err, &ErrInvalidCid{}) {
+			t.Fatal("expected error to be &ErrInvalidCid")
+		}
+	}
+
+	_, err := Decode("")
+	run(err)
+
+	_, err = Decode("not-a-cid")
+	run(err)
+
+	_, err = Decode("bafyInvalid")
+	run(err)
+
+	_, err = Decode("QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zIII")
+	run(err)
+
+	_, err = Cast([]byte("invalid"))
+	run(err)
+
+	_, err = Parse("not-a-cid")
+	run(err)
+
+	_, err = Parse("bafyInvalid")
+	run(err)
+
+	_, err = Parse("QmdfTbBqBPQ7VNxZEYEj14VmRuZBkqFbiwReogJgS1zIII")
+	run(err)
+
+	_, err = Parse(123)
+	run(err)
+
+	_, _, err = CidFromBytes([]byte("invalid"))
+	run(err)
+
+	_, err = Prefix{}.Sum([]byte("data"))
+	run(err)
+
+	_, err = PrefixFromBytes([]byte{0x80})
+	run(err)
+
+	_, err = ExtractEncoding("invalid ")
+	run(err)
+
+}

go.mod

@@ -13,8 +13,8 @@ require (
 	github.com/mr-tron/base58 v1.2.0 // indirect
 	github.com/multiformats/go-base32 v0.0.3 // indirect
 	github.com/multiformats/go-base36 v0.1.0 // indirect
-	golang.org/x/crypto v0.0.0-20210506145944-38f3c27a63bf // indirect
-	golang.org/x/sys v0.0.0-20210309074719-68d13333faf2 // indirect
+	golang.org/x/crypto v0.1.0 // indirect
+	golang.org/x/sys v0.1.0 // indirect
 )
 
-go 1.18
+go 1.19

go.sum

@@ -19,12 +19,13 @@ github.com/multiformats/go-varint v0.0.6 h1:gk85QWKxh3TazbLxED/NlDVv8+q+ReFJk7Y2
 github.com/multiformats/go-varint v0.0.6/go.mod h1:3Ls8CIEsrijN6+B7PbrXRPxHRPuXSrVKRY101jdMZYE=
 golang.org/x/crypto v0.0.0-20190308221718-c2843e01d9a2/go.mod h1:djNgcEr1/C05ACkg1iLfiJU5Ep61QUkGW8qpdssI0+w=
 golang.org/x/crypto v0.0.0-20210220033148-5ea612d1eb83/go.mod h1:jdWPYTVW3xRLrWPugEBEK3UY2ZEsg3UU495nc5E+M+I=
-golang.org/x/crypto v0.0.0-20210506145944-38f3c27a63bf h1:B2n+Zi5QeYRDAEodEu72OS36gmTWjgpXr2+cWcBW90o=
-golang.org/x/crypto v0.0.0-20210506145944-38f3c27a63bf/go.mod h1:P+XmwS30IXTQdn5tA2iutPOUgjI07+tq3H3K9MVA1s8=
+golang.org/x/crypto v0.1.0 h1:MDRAIl0xIo9Io2xV565hzXHw3zVseKrJKodhohM5CjU=
+golang.org/x/crypto v0.1.0/go.mod h1:RecgLatLF4+eUMCP1PoPZQb+cVrJcOPbHkTkbkB9sbw=
 golang.org/x/net v0.0.0-20190404232315-eb5bcb51f2a3/go.mod h1:t9HGtf8HONx5eT2rtn7q6eTqICYqUVnKs3thJo3Qplg=
 golang.org/x/sys v0.0.0-20190215142949-d0b11bdaac8a/go.mod h1:STP8DvDyc/dI5b8T5hshtkjS+E42TnysNCUPdjciGhY=
 golang.org/x/sys v0.0.0-20191026070338-33540a1f6037/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
-golang.org/x/sys v0.0.0-20210309074719-68d13333faf2 h1:46ULzRKLh1CwgRq2dC5SlBzEqqNCi8rreOZnNrbqcIY=
 golang.org/x/sys v0.0.0-20210309074719-68d13333faf2/go.mod h1:h1NjWce9XRLGQEsW7wpKNCjG9DtNlClVuFLEZdDNbEs=
+golang.org/x/sys v0.1.0 h1:kunALQeHf1/185U1i0GOB/fy1IPRDDpuoOOqRReG57U=
+golang.org/x/sys v0.1.0/go.mod h1:oPkhp1MJrh7nUepCBck5+mAzfO9JrbApNNgaTdGDITg=
 golang.org/x/term v0.0.0-20201117132131-f5c789dd3221/go.mod h1:Nr5EML6q2oocZ2LXRh80K7BxOlk5/8JxuGnuhpl+muw=
 golang.org/x/text v0.3.0/go.mod h1:NqM8EUOU14njkJ3fqMW+pc6Ldnwhi/IjpwHt7yyuwOQ=

version.json

@@ -1,3 +1,3 @@
 {
-  "version": "v0.3.2"
+  "version": "v0.4.1"
 }