Add try / catch unit tests (#857)

test/sources/solidity/contracts/try/try-catch-empty-blocks.sol

@@ -0,0 +1,11 @@
+pragma solidity >=0.8.0 <0.9.0;
+
+contract Test {
+    function op(bool y) external {
+      require(y);
+    }
+
+    function a(bool x) external {
+        try this.op(x) { } catch { }
+    }
+}

test/sources/solidity/contracts/try/try-error-block.sol

@@ -0,0 +1,16 @@
+pragma solidity >=0.8.0 <0.9.0;
+
+contract Test {
+    function op(bool y) external returns (uint){
+      require(y, "sorry");
+      return 1;
+    }
+
+    function a(bool x) external returns (uint) {
+        try this.op(x) returns (uint v) {
+            return v;
+        } catch Error(string memory /*reason*/) {
+            return 0;
+        }
+    }
+}

test/sources/solidity/contracts/try/try-multi-block.sol

@@ -0,0 +1,29 @@
+pragma solidity >=0.8.0 <0.9.0;
+
+contract Test {
+    function op(uint y) external returns (uint){
+      uint a = 100;
+      uint b = 0;
+
+      if (y == 0)
+        return 0;
+      if (y == 1)
+        require(false, 'sorry');
+      if (y == 2)
+        uint x = (a / b);
+      if (y == 3)
+        revert();
+    }
+
+    function a(uint x) external returns (uint) {
+        try this.op(x) returns (uint v) {
+            return 0;
+        } catch Error(string memory /*reason*/) {
+            return 1;
+        } catch Panic(uint /*errorCode*/) {
+            return 2;
+        } catch (bytes memory /*lowLevelData*/) {
+            return 3;
+        }
+    }
+}

test/sources/solidity/contracts/try/try-panic-block.sol

@@ -0,0 +1,16 @@
+pragma solidity >=0.8.0 <0.9.0;
+
+contract Test {
+    function op(bool y) external returns (uint){
+      uint x = 100 / 0;
+      return x;
+    }
+
+    function a(bool x) external pure returns (uint) {
+        try this.op(x) returns (uint v) {
+            return v;
+        } catch Panic(uint /*errorCode*/) {
+            return 0;
+        }
+    }
+}

test/sources/solidity/contracts/try/try-revert-block.sol

@@ -0,0 +1,15 @@
+pragma solidity >=0.8.0 <0.9.0;
+
+contract Test {
+    function op(bool y) external returns (uint){
+      if (y == false) revert();
+    }
+
+    function a(bool x) external pure returns (uint) {
+        try this.op(x) returns (uint v) {
+            return v;
+        } catch (bytes memory /*lowLevelData*/) {
+            return 0;
+        }
+    }
+}

test/units/try.js

@@ -0,0 +1,123 @@
+const assert = require('assert');
+const util = require('./../util/util.js');
+const Coverage = require('./../../lib/coverage');
+const Api = require('./../../lib/api')
+
+describe.only('try / catch branches', () => {
+  let coverage;
+  let api;
+
+  before(async () => api = new Api({silent: true}));
+  beforeEach(() => coverage = new Coverage());
+  after(async() => await api.finish());
+
+  it('should cover a try/catch statement with empty blocks (success branch only)', async function() {
+    const contract = await util.bootstrapCoverage('try/try-catch-empty-blocks', api, this.provider, );
+    coverage.addContract(contract.instrumented, util.filePath);
+    await contract.instance.a(true, contract.gas);
+    const mapping = coverage.generate(contract.data, util.pathPrefix);
+
+    assert.deepEqual(mapping[util.filePath].l, {
+      5:1,9:1
+    });
+    assert.deepEqual(mapping[util.filePath].b, {
+      1:[1,0]
+    });
+    assert.deepEqual(mapping[util.filePath].s, {
+      1:1,2:1
+    });
+    assert.deepEqual(mapping[util.filePath].f, {
+      1:1,2:1
+    });
+  });
+
+  it('should cover a try/catch statement with empty blocks (both branches)', async function() {
+    const contract = await util.bootstrapCoverage('try/try-catch-empty-blocks', api, this.provider, );
+    coverage.addContract(contract.instrumented, util.filePath);
+    await contract.instance.a(true, contract.gas);
+
+    try { await contract.instance.a(false, contract.gas) } catch(err) { /* ignore */ }
+
+    const mapping = coverage.generate(contract.data, util.pathPrefix);
+
+    assert.deepEqual(mapping[util.filePath].l, {
+      5:2,9:2
+    });
+    assert.deepEqual(mapping[util.filePath].b, {
+      1:[1,1]
+    });
+    assert.deepEqual(mapping[util.filePath].s, {
+      1:2,2:2
+    });
+    assert.deepEqual(mapping[util.filePath].f, {
+      1:2,2:2
+    });
+  });
+
+  it('should cover a try/catch statement with an Error block (success branch only)', async function() {
+    const contract = await util.bootstrapCoverage('try/try-error-block', api, this.provider, );
+    coverage.addContract(contract.instrumented, util.filePath);
+    await contract.instance.a(true, contract.gas);
+
+    const mapping = coverage.generate(contract.data, util.pathPrefix);
+
+    assert.deepEqual(mapping[util.filePath].l, {
+      5:1,6:1,10:1,11:1,13:0
+    });
+    assert.deepEqual(mapping[util.filePath].b, {
+      1:[1,0]
+    });
+    assert.deepEqual(mapping[util.filePath].s, {
+      1:1,2:1,3:1,4:1,5:0
+    });
+    assert.deepEqual(mapping[util.filePath].f, {
+      1:1,2:1
+    });
+  });
+
+  it('should cover a try/catch statement with an Error block (both branches)', async function() {
+    const contract = await util.bootstrapCoverage('try/try-error-block', api, this.provider, );
+    coverage.addContract(contract.instrumented, util.filePath);
+
+    await contract.instance.a(true, contract.gas);
+    try { await contract.instance.a(false, contract.gas) } catch(err) { /* ignore */ }
+
+    const mapping = coverage.generate(contract.data, util.pathPrefix);
+
+    assert.deepEqual(mapping[util.filePath].l, {
+      5:2,6:1,10:2,11:1,13:1
+    });
+    assert.deepEqual(mapping[util.filePath].b, {
+      1:[1,1]
+    });
+    assert.deepEqual(mapping[util.filePath].s, {
+      1:2,2:1,3:2,4:1,5:1
+    });
+    assert.deepEqual(mapping[util.filePath].f, {
+      1:2,2:2
+    });
+  });
+
+  it('should cover a try/catch statement with multi-block catch clauses (middle-block)', async function() {
+    const contract = await util.bootstrapCoverage('try/try-multi-block', api, this.provider, );
+    coverage.addContract(contract.instrumented, util.filePath);
+
+    await contract.instance.a(0, contract.gas);
+    try { await contract.instance.a(2, contract.gas) } catch(err) { /* ignore */ }
+
+    const mapping = coverage.generate(contract.data, util.pathPrefix);
+
+    assert.deepEqual(mapping[util.filePath].l, {
+      5:2,6:2,8:2,9:1,10:1,11:0,12:1,13:1,14:0,15:0,19:2,20:1,22:0,24:1,26:0
+    });
+    assert.deepEqual(mapping[util.filePath].b, {
+      1:[1,1],2:[0,1],3:[0,0],4:[1,0],5:[0,0]
+    });
+    assert.deepEqual(mapping[util.filePath].s, {
+      1:2,2:2,3:2,4:1,5:1,6:0,7:1,8:1,9:0,10:0,11:2,12:1,13:0,14:1,15:0
+    });
+    assert.deepEqual(mapping[util.filePath].f, {
+      1:2,2:2
+    });
+  });
+});