Add simple concattenated string support

Signed-off-by: Peter Broadhurst <[email protected]>

pkg/abi/abi.go

@@ -439,6 +439,30 @@ func (e *Entry) String() string {
 	return s
 }
 
+// SolString returns a Solidity - like string, with an empty function definition,
+// and any struct definitions separated afterwards with a ; (semicolon)
+func (e *Entry) SolString() string {
+	solStr, err := e.SolidityStringCtx(context.Background())
+	if err != nil {
+		log.L(context.Background()).Warnf("ABI parsing failed: %s", err)
+	}
+	return solStr
+}
+
+func (e *Entry) SolidityStringCtx(ctx context.Context) (string, error) {
+	solDef, childStructs, err := e.SolidityDefCtx(ctx)
+	if err != nil {
+		return "", err
+	}
+	buff := new(strings.Builder)
+	buff.WriteString(solDef)
+	for _, e := range childStructs {
+		buff.WriteString("; ")
+		buff.WriteString(e)
+	}
+	return buff.String(), nil
+}
+
 func (e *Entry) Signature() (string, error) {
 	return e.SignatureCtx(context.Background())
 }

pkg/abi/abi_test.go

@@ -740,6 +740,8 @@ func TestSignatureHashInvalid(t *testing.T) {
 	_, _, err = e.SolidityDef()
 	assert.Regexp(t, "FF22025", err)
 
+	assert.Empty(t, e.SolString())
+
 	assert.Equal(t, make(ethtypes.HexBytes0xPrefix, 32), e.SignatureHashBytes())
 
 	e = &Entry{
@@ -1008,6 +1010,9 @@ func TestComplexStructSolidityDef(t *testing.T) {
 		"struct Invoice { Customer customer; Widget[] widgets; }",
 	}, childStructs)
 
+	assert.Equal(t, "function invoice(Invoice memory _invoice) external payable { }; struct Customer { address owner; bytes32 locator; }; struct Widget { string description; uint256 price; string[] attributes; }; struct Invoice { Customer customer; Widget[] widgets; }",
+		abi.Functions()["invoice"].SolString())
+
 	solDef, childStructs, err = abi.Events()["Invoiced"].SolidityDef()
 	assert.NoError(t, err)
 	assert.Equal(t, "event Invoiced(Customer customer, Widget[] widgets)", solDef)