Merge #11220: Check specific validation error in miner tests

12781db [Tests] check specific validation error in miner tests (Sjors Provoost)

Pull request description:

  ## Problem

  `BOOST_CHECK_THROW` merely checks that some `std::runtime_error` is
  thrown, but not which one.

  Here's an example of how this can cause a test to pass when a developer
  introduces a consensus bug. The test for the sigops limit assumes
  that `CreateNewBlock` fails with `bad-blk-sigops`. However it can
  also fail with bad-txns-vout-negative, if a naive developer lowers
  `BLOCKSUBSIDY` to `1*COIN`.

  ## Solution

  `BOOST_CHECK_EXCEPTION` allows an additional predicate function. This
  commit uses this for all exceptions that are checked for in
  `miner_tets.cpp`:
  * `bad-blk-sigops`
  * `bad-cb-multiple`
  * `bad-txns-inputs-missingorspent`
  * `block-validation-failed`

  If the function throws a different error, the test will fail. Although the message produced by Boost is a bit [confusing](http://boost.2283326.n4.nabble.com/Test-BOOST-CHECK-EXCEPTION-error-message-still-vague-tt4683257.html#a4683554), it does show which error was actually thrown. Here's what the above `1*COIN` bug would result in:

  <img width="1134" alt="schermafbeelding 2017-09-02 om 23 42 29" src="https://user-images.githubusercontent.com/10217/29998976-815cabce-9038-11e7-9c46-f5f6cfb0ca7d.png">

  ## Other considerations

  A more elegant solution in my opinion would be to subclass `std::runtime_error` for each `INVALID_TRANSACTION` type, but this would involve touching consensus code.

  I put the predicates in `test_bitcoin.h` because I assume they can be reused in other test files. However [serialize_tests.cpp](https://github.com/bitcoin/bitcoin/blob/v0.15.0rc3/src/test/serialize_tests.cpp#L245) also uses `BOOST_CHECK_EXCEPTION` and it defines the predicate in the test file itself.

  Instead of four `IsRejectInvalidReasonX(std::runtime_error const& e)` functions, I'd prefer something reusable like `bool IsRejectInvalidReason(String reason)(std::runtime_error const& e)`, which would be used like `BOOST_CHECK_EXCEPTION(functionThatThrows(), std::runtime_error, IsRejectInvalidReason("bad-blk-sigops")`. I couldn't figure out how to do that in C++.

Tree-SHA512: e364f19b4ac19f910f6e8d6533357f57ccddcbd9d53dcfaf923d424d2b9711446d6f36da193208b35788ca21863eadaa7becd9ad890334d334bccf8c2e63dee1

src/test/miner_tests.cpp

@@ -26,6 +26,17 @@
 
 BOOST_FIXTURE_TEST_SUITE(miner_tests, TestingSetup)
 
+// BOOST_CHECK_EXCEPTION predicates to check the specific validation error
+class HasReason {
+public:
+    HasReason(const std::string& reason) : m_reason(reason) {}
+    bool operator() (const std::runtime_error& e) const {
+        return std::string(e.what()).find(m_reason) != std::string::npos;
+    };
+private:
+    const std::string m_reason;
+};
+
 static CFeeRate blockMinFeeRate = CFeeRate(DEFAULT_BLOCK_MIN_TX_FEE);
 
 static BlockAssembler AssemblerForTest(const CChainParams& params) {
@@ -264,7 +275,8 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
         mempool.addUnchecked(hash, entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(spendsCoinbase).FromTx(tx));
         tx.vin[0].prevout.hash = hash;
     }
-    BOOST_CHECK_THROW(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error);
+
+    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("bad-blk-sigops"));
     mempool.clear();
 
     tx.vin[0].prevout.hash = txFirst[0]->GetHash();
@@ -304,7 +316,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
     // orphan in mempool, template creation fails
     hash = tx.GetHash();
     mempool.addUnchecked(hash, entry.Fee(LOWFEE).Time(GetTime()).FromTx(tx));
-    BOOST_CHECK_THROW(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error);
+    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("bad-txns-inputs-missingorspent"));
     mempool.clear();
 
     // child with higher feerate than parent
@@ -332,7 +344,8 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
     hash = tx.GetHash();
     // give it a fee so it'll get mined
     mempool.addUnchecked(hash, entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(false).FromTx(tx));
-    BOOST_CHECK_THROW(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error);
+    // Should throw bad-cb-multiple
+    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("bad-cb-multiple"));
     mempool.clear();
 
     // double spend txn pair in mempool, template creation fails
@@ -345,7 +358,7 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
     tx.vout[0].scriptPubKey = CScript() << OP_2;
     hash = tx.GetHash();
     mempool.addUnchecked(hash, entry.Fee(HIGHFEE).Time(GetTime()).SpendsCoinbase(true).FromTx(tx));
-    BOOST_CHECK_THROW(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error);
+    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("bad-txns-inputs-missingorspent"));
     mempool.clear();
 
     // subsidy changing
@@ -389,7 +402,8 @@ BOOST_AUTO_TEST_CASE(CreateNewBlock_validity)
     tx.vout[0].nValue -= LOWFEE;
     hash = tx.GetHash();
     mempool.addUnchecked(hash, entry.Fee(LOWFEE).Time(GetTime()).SpendsCoinbase(false).FromTx(tx));
-    BOOST_CHECK_THROW(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error);
+    // Should throw block-validation-failed
+    BOOST_CHECK_EXCEPTION(AssemblerForTest(chainparams).CreateNewBlock(scriptPubKey), std::runtime_error, HasReason("block-validation-failed"));
     mempool.clear();
 
     // Delete the dummy blocks again.