test: pin BYTECODE_HASH, assert word-opcode alignment, verify FLRETH rate reciprocity

test/src/concrete/FlareFtsoWords.pointers.t.sol

@@ -14,6 +14,19 @@ import {
 } from "src/concrete/FlareFtsoWords.sol";
 import {LibGenParseMeta} from "rain-interpreter-interface-0.1.0/src/lib/codegen/LibGenParseMeta.sol";
 import {LibFlareFtsoSubParser} from "src/lib/parse/LibFlareFtsoSubParser.sol";
+import {BYTECODE_HASH} from "src/generated/FlareFtsoWords.pointers.sol";
+import {
+    SUB_PARSER_WORD_FTSO_CURRENT_PRICE_USD,
+    SUB_PARSER_WORD_FTSO_CURRENT_PRICE_PAIR,
+    SUB_PARSER_WORD_SFLR_EXCHANGE_RATE,
+    SUB_PARSER_WORD_PARSERS_LENGTH
+} from "src/lib/parse/LibFlareFtsoSubParser.sol";
+import {
+    OPCODE_FTSO_CURRENT_PRICE_USD,
+    OPCODE_FTSO_CURRENT_PRICE_PAIR,
+    OPCODE_SLFR_CURRENT_EXCHANGE_RATE,
+    OPCODE_FUNCTION_POINTERS_LENGTH
+} from "src/abstract/FlareFtsoExtern.sol";
 
 contract FlareFtsoWordsPointersTest is Test {
     function testIntegrityPointers() external {
@@ -42,4 +55,26 @@ contract FlareFtsoWordsPointersTest is Test {
         bytes memory expected = LibGenParseMeta.buildParseMetaV2(authoringMeta, 2);
         assertEq(SUB_PARSER_PARSE_META, expected);
     }
+
+    /// #63 — committed BYTECODE_HASH is verified against the actual compiled contract
+    /// so any bytecode drift (optimizer change, solc bump, library edit) fires CI red.
+    function testBytecodeHash() external {
+        FlareFtsoWords flareFtsoWords = new FlareFtsoWords();
+        assertEq(address(flareFtsoWords).codehash, BYTECODE_HASH, "BYTECODE_HASH drifted from compiled bytecode");
+    }
+
+    /// #64 — both index-constant sets must agree element-for-element; any reorder
+    /// in either file that breaks the pairing is caught without a fork or RPC.
+    function testWordOpcodeIndicesAligned() external pure {
+        assertEq(SUB_PARSER_WORD_FTSO_CURRENT_PRICE_USD, OPCODE_FTSO_CURRENT_PRICE_USD);
+        assertEq(SUB_PARSER_WORD_FTSO_CURRENT_PRICE_PAIR, OPCODE_FTSO_CURRENT_PRICE_PAIR);
+        assertEq(SUB_PARSER_WORD_SFLR_EXCHANGE_RATE, OPCODE_SLFR_CURRENT_EXCHANGE_RATE);
+        assertEq(SUB_PARSER_WORD_PARSERS_LENGTH, OPCODE_FUNCTION_POINTERS_LENGTH);
+
+        bytes memory authoringMetaBytes = LibFlareFtsoSubParser.authoringMetaV2();
+        AuthoringMetaV2[] memory meta = abi.decode(authoringMetaBytes, (AuthoringMetaV2[]));
+        assertEq(meta[OPCODE_FTSO_CURRENT_PRICE_USD].word, bytes32("ftso-current-price-usd"));
+        assertEq(meta[OPCODE_FTSO_CURRENT_PRICE_PAIR].word, bytes32("ftso-current-price-pair"));
+        assertEq(meta[OPCODE_SLFR_CURRENT_EXCHANGE_RATE].word, bytes32("sflr-exchange-rate"));
+    }
 }

test/src/lib/flreth/LibDineroFlrEth.t.sol

@@ -22,4 +22,13 @@ contract LibDineroFlrEthTest is Test {
         uint256 rate18 = LibDineroFlrEth.getFLRETHPerETH18();
         assertEq(rate18, 0.989103076939285809e18);
     }
+
+    /// #62 — asserts getETHPerFLRETH18 and getFLRETHPerETH18 are reciprocals of each
+    /// other within 0.1%. An inverted direction mapping between LSTPerToken /
+    /// tokensPerLST and the wrappers would produce a product far from 1e36.
+    function testRatesAreReciprocal() external view {
+        uint256 ethPerFlreth = LibDineroFlrEth.getETHPerFLRETH18();
+        uint256 flrethPerEth = LibDineroFlrEth.getFLRETHPerETH18();
+        assertApproxEqRel(ethPerFlreth * flrethPerEth, 1e36, 1e15);
+    }
 }