erasure-coding: do not panic on 1 validator (#2022)

* erasure-coding: do not panic on 1 validator

* tabify fuzz tests

* remove num_validators length check

* remove unused import

* move erasure_coding_fuzzer to fuzzer

* change the authors to admit (at) parity.io

* Apply suggestions from code review

Co-authored-by: Sergei Shulepov <sergei@parity.io>

Co-authored-by: Sergei Shulepov <sergei@parity.io>

polkadot/erasure-coding/fuzzer/src/reconstruct.rs

@@ -0,0 +1,16 @@
+use polkadot_erasure_coding::*;
+use primitives::v1::AvailableData;
+use honggfuzz::fuzz;
+
+fn main() {
+	loop {
+		fuzz!(|data: (usize, Vec<(Vec<u8>, usize)>)| {
+			let (num_validators, chunk_input) = data;
+			let reconstructed: Result<AvailableData, _> = reconstruct_v1(
+				num_validators,
+				chunk_input.iter().map(|t| (&*t.0, t.1)).collect::<Vec<(&[u8], usize)>>()
+			);
+			println!("reconstructed {:?}", reconstructed);
+		});
+	}
+}