From bb4251fafa72756687f914dfa43050a9232a8bde Mon Sep 17 00:00:00 2001
From: Nicolas Peugnet <nicolas.peugnet@lip6.fr>
Date: Tue, 7 Jul 2026 13:31:02 +0200
Subject: [PATCH 1/2] Log the parsed tokens on failure in fuzz test

---
 tokenizer_test.go | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/tokenizer_test.go b/tokenizer_test.go
index 196b630..06225e8 100644
--- a/tokenizer_test.go
+++ b/tokenizer_test.go
@@ -389,14 +389,14 @@ func FuzzStream(f *testing.F) {
 
 		stream := tokenizer.ParseStream(buffer, 100)
 		var actual []byte
+		var tokens []*Token
 		for stream.IsValid() {
 			current := stream.CurrentToken()
-			// t.Logf("%#v", current)
+			tokens = append(tokens, current)
 			actual = append(actual, current.Indent()...)
 			actual = append(actual, current.Value()...)
 			stream.GoNext()
 		}
-		// t.Logf("%#v", stream.CurrentToken())
 
 		// As we only concatenate the indents of each token, the trailing
 		// whitespaces and token separators are lost, so we trim these
@@ -405,6 +405,7 @@ func FuzzStream(f *testing.F) {
 		expected := bytes.TrimRight(origBytes, trimset)
 		actual = bytes.TrimRight(actual, trimset)
 		if !bytes.Equal(expected, actual) {
+			t.Log(tokens)
 			t.Errorf("input:\n%q\nexpected:\n%q\nactual:\n%q", orig, expected, actual)
 		}
 	})

From d236d62d1648d244b7db3c33140c0e854a6ed3db Mon Sep 17 00:00:00 2001
From: Nicolas Peugnet <nicolas.peugnet@lip6.fr>
Date: Tue, 7 Jul 2026 10:47:33 +0200
Subject: [PATCH 2/2] Fix parsing of ".E0" input

---
 parser.go                                 | 2 +-
 testdata/fuzz/FuzzStream/0989a2a2ef3fb8ff | 2 ++
 tokenizer_test.go                         | 5 +++++
 3 files changed, 8 insertions(+), 1 deletion(-)
 create mode 100644 testdata/fuzz/FuzzStream/0989a2a2ef3fb8ff

diff --git a/parser.go b/parser.go
index 6db0e8b..56efab8 100644
--- a/parser.go
+++ b/parser.go
@@ -297,7 +297,7 @@ func (p *parsing) parseNumber() bool {
 				if start == -1 { // floats can be started from a pointer
 					start = p.pos
 				}
-			} else if !(nextByte == 'e' || nextByte == 'E' || nextByte == 0) {
+			} else if !((nextByte == 'e' || nextByte == 'E') && hasNumber) && nextByte != 0 {
 				break
 			}
 			floatTraitPos = p.pos
diff --git a/testdata/fuzz/FuzzStream/0989a2a2ef3fb8ff b/testdata/fuzz/FuzzStream/0989a2a2ef3fb8ff
new file mode 100644
index 0000000..de70513
--- /dev/null
+++ b/testdata/fuzz/FuzzStream/0989a2a2ef3fb8ff
@@ -0,0 +1,2 @@
+go test fuzz v1
+string(".E0")
diff --git a/tokenizer_test.go b/tokenizer_test.go
index 06225e8..e302b16 100644
--- a/tokenizer_test.go
+++ b/tokenizer_test.go
@@ -158,6 +158,11 @@ func TestTokenizeEdgeCases(t *testing.T) {
 			}},
 			{"\x00", []Token{ // https://github.com/bzick/tokenizer/issues/28
 			}},
+			{".E0", []Token{ // https://github.com/bzick/tokenizer/issues/42
+				{key: TokenUnknown, value: s2b("."), offset: 0, line: 1, id: 0},
+				{key: TokenKeyword, value: s2b("E"), offset: 1, line: 1, id: 1},
+				{key: TokenInteger, value: s2b("0"), offset: 2, line: 1, id: 2},
+			}},
 		}
 		for _, v := range data1 {
 			t.Run(v.str, func(t *testing.T) {