From 7061943d520bbaaa14fbad4cd54e74a248f02456 Mon Sep 17 00:00:00 2001
From: Valery Aligorsky <stdammit@gmail.com>
Date: Sat, 28 Aug 2021 11:33:25 +0200
Subject: [PATCH] feat(sol-0.8): add support for errors exports

---
 lib/antlr/visitors/exportVisitor.ts    | 38 +++++++++++++++++++++++++-
 lib/types.ts                           |  1 +
 test/compiled/ContractWithEvents.sol   | 12 ++++++++
 test/compiled/ContractsWithErrors.sol  | 19 +++++++++++++
 test/contracts/ContractWithEvents.sol  | 11 ++++++++
 test/contracts/ContractsWithErrors.sol | 18 ++++++++++++
 test/index.spec.ts                     |  8 ++++++
 7 files changed, 106 insertions(+), 1 deletion(-)
 create mode 100644 test/compiled/ContractWithEvents.sol
 create mode 100644 test/compiled/ContractsWithErrors.sol
 create mode 100644 test/contracts/ContractWithEvents.sol
 create mode 100644 test/contracts/ContractsWithErrors.sol

diff --git a/lib/antlr/visitors/exportVisitor.ts b/lib/antlr/visitors/exportVisitor.ts
index ed500df..0328c90 100644
--- a/lib/antlr/visitors/exportVisitor.ts
+++ b/lib/antlr/visitors/exportVisitor.ts
@@ -6,7 +6,7 @@ import { SolidityParserListener } from '../generated/SolidityParserListener';
 import {
   ContractDefinitionContext,
   EnumDefinitionContext,
-  InheritanceSpecifierContext,
+  ErrorDefinitionContext,
   InheritanceSpecifierListContext,
   InterfaceDefinitionContext,
   LibraryDefinitionContext,
@@ -305,4 +305,40 @@ class ExportVisitor implements SolidityParserListener {
       name: name.text,
     });
   }
+
+  enterErrorDefinition(ctx: ErrorDefinitionContext): void {
+    if (!(ctx.parent instanceof SourceUnitContext)) {
+      return;
+    }
+
+    if (!ctx.stop) {
+      return;
+    }
+
+    if (!ctx.children) {
+      return;
+    }
+
+    const start = ctx.start.startIndex;
+    const end = ctx.stop.stopIndex;
+    const name = ctx.identifier();
+    if (!name?.stop) {
+      return;
+    }
+
+    const bodyStart = name.stop.stopIndex;
+
+    this.#onVisit({
+      start,
+      end,
+      abstract: false,
+      type: ExportType.error,
+      body: {
+        start: bodyStart + 1,
+        end,
+      },
+      is: null,
+      name: name.text,
+    });
+  }
 }
diff --git a/lib/types.ts b/lib/types.ts
index ccc188c..edfb3e7 100644
--- a/lib/types.ts
+++ b/lib/types.ts
@@ -7,6 +7,7 @@ export enum ExportType {
   struct = 'struct',
   enum = 'enum',
   comment = 'comment',
+  error = 'error',
 }
 
 export interface ExportPluginProcessor {
diff --git a/test/compiled/ContractWithEvents.sol b/test/compiled/ContractWithEvents.sol
new file mode 100644
index 0000000..0db9c29
--- /dev/null
+++ b/test/compiled/ContractWithEvents.sol
@@ -0,0 +1,12 @@
+pragma solidity ^0.8.4;
+
+
+// SPDX-License-Identifier: GPL-3.0
+contract SimpleAuction {
+    event HighestBidIncreased(address bidder, uint amount); // Event
+
+    function bid() public payable {
+        // ...
+        emit HighestBidIncreased(msg.sender, msg.value); // Triggering event
+    }
+}
diff --git a/test/compiled/ContractsWithErrors.sol b/test/compiled/ContractsWithErrors.sol
new file mode 100644
index 0000000..057c44d
--- /dev/null
+++ b/test/compiled/ContractsWithErrors.sol
@@ -0,0 +1,19 @@
+pragma solidity ^0.8.4;
+
+
+// SPDX-License-Identifier: GPL-3.0
+/// Not enough funds for transfer. Requested `requested`,
+/// but only `available` available.
+error NotEnoughFunds (uint requested, uint available);
+
+contract Token {
+    mapping(address => uint) balances;
+    function transfer(address to, uint amount) public {
+        uint balance = balances[msg.sender];
+        if (balance < amount)
+            revert NotEnoughFunds(amount, balance);
+        balances[msg.sender] -= amount;
+        balances[to] += amount;
+        // ...
+    }
+}
diff --git a/test/contracts/ContractWithEvents.sol b/test/contracts/ContractWithEvents.sol
new file mode 100644
index 0000000..12b6c0f
--- /dev/null
+++ b/test/contracts/ContractWithEvents.sol
@@ -0,0 +1,11 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity ^0.8.4;
+
+contract SimpleAuction {
+    event HighestBidIncreased(address bidder, uint amount); // Event
+
+    function bid() public payable {
+        // ...
+        emit HighestBidIncreased(msg.sender, msg.value); // Triggering event
+    }
+}
diff --git a/test/contracts/ContractsWithErrors.sol b/test/contracts/ContractsWithErrors.sol
new file mode 100644
index 0000000..40653ca
--- /dev/null
+++ b/test/contracts/ContractsWithErrors.sol
@@ -0,0 +1,18 @@
+// SPDX-License-Identifier: GPL-3.0
+pragma solidity ^0.8.4;
+
+/// Not enough funds for transfer. Requested `requested`,
+/// but only `available` available.
+error NotEnoughFunds(uint requested, uint available);
+
+contract Token {
+    mapping(address => uint) balances;
+    function transfer(address to, uint amount) public {
+        uint balance = balances[msg.sender];
+        if (balance < amount)
+            revert NotEnoughFunds(amount, balance);
+        balances[msg.sender] -= amount;
+        balances[to] += amount;
+        // ...
+    }
+}
diff --git a/test/index.spec.ts b/test/index.spec.ts
index 57de7c5..1aec753 100644
--- a/test/index.spec.ts
+++ b/test/index.spec.ts
@@ -112,4 +112,12 @@ describe('Solidity Merger', () => {
   it('should compile file with checked/unckecked arithmetic operations (0.8 support)', async () => {
     await testFile('CheckedUnchecked');
   });
+
+  it('should compile file with errors', async () => {
+    await testFile('ContractsWithErrors');
+  });
+
+  it('should compile file with events', async () => {
+    await testFile('ContractWithEvents');
+  });
 });