Moved ethutil => common

common/natspec/natspec.go

@@ -0,0 +1,63 @@
+package natspec
+
+import (
+	"fmt"
+	"github.com/obscuren/otto"
+)
+
+type NatSpec struct {
+	jsvm *otto.Otto
+}
+
+// TODO: should initialise with abi and userdoc jsons
+func New() (self *NatSpec, err error) {
+
+	self = new(NatSpec)
+	self.jsvm = otto.New()
+
+	_, err = self.jsvm.Run(natspecJS)
+	if err != nil {
+		return
+	}
+	_, err = self.jsvm.Run("var natspec = require('natspec');")
+	if err != nil {
+		return
+	}
+
+	return
+}
+
+func (self *NatSpec) Notice(transaction, abi, method, expression string) (string, error) {
+	var err error
+	if _, err = self.jsvm.Run("var transaction = " + transaction + ";"); err != nil {
+		return "", fmt.Errorf("natspec.js error setting transaction: %v", err)
+	}
+
+	if _, err = self.jsvm.Run("var abi = " + abi + ";"); err != nil {
+		return "", fmt.Errorf("natspec.js error setting abi: %v", err)
+	}
+
+	if _, err = self.jsvm.Run("var method = '" + method + "';"); err != nil {
+		return "", fmt.Errorf("natspec.js error setting method: %v", err)
+	}
+
+	if _, err = self.jsvm.Run("var expression = \"" + expression + "\";"); err != nil {
+		return "", fmt.Errorf("natspec.js error setting expression: %v", err)
+	}
+
+	self.jsvm.Run("var call = {method: method,abi: abi,transaction: transaction};")
+	value, err := self.jsvm.Run("natspec.evaluateExpression(expression, call);")
+	if err != nil {
+		return "", fmt.Errorf("natspec.js error evaluating expression: %v", err)
+	}
+	evalError := "Natspec evaluation failed, wrong input params"
+	if value.String() == evalError {
+		return "", fmt.Errorf("natspec.js error evaluating expression: wrong input params in expression '%s'", expression)
+	}
+	if len(value.String()) == 0 {
+		return "", fmt.Errorf("natspec.js error evaluating expression")
+	}
+
+	return value.String(), nil
+
+}

common/natspec/natspec_test.go

@@ -0,0 +1,97 @@
+package natspec
+
+import (
+	"testing"
+)
+
+func TestNotice(t *testing.T) {
+
+	tx := `
+	{
+    "jsonrpc": "2.0",
+    "method": "eth_call",
+    "params": [{
+        "to": "0x8521742d3f456bd237e312d6e30724960f72517a",
+        "data": "0xc6888fa1000000000000000000000000000000000000000000000000000000000000007a"
+    }],
+    "id": 6
+  }
+	`
+
+	abi := `
+	[{
+    "name": "multiply",
+    "constant": false,
+    "type": "function",
+    "inputs": [{
+      "name": "a",
+      "type": "uint256"
+    }],
+    "outputs": [{
+      "name": "d",
+      "type": "uint256"
+    }]
+  }]
+	`
+
+	desc := "Will multiply `a` by 7 and return `a * 7`."
+
+	method := "multiply"
+
+	ns, err := New()
+	if err != nil {
+		t.Errorf("NewNATSpec error %v", err)
+	}
+
+	notice, err := ns.Notice(tx, abi, method, desc)
+
+	if err != nil {
+		t.Errorf("expected no error got %v", err)
+	}
+
+	expected := "Will multiply 122 by 7 and return 854."
+	if notice != expected {
+		t.Errorf("incorrect notice. expected %v, got %v", expected, notice)
+	} else {
+		t.Logf("returned notice \"%v\"", notice)
+	}
+
+	notice, err = ns.Notice(tx, abi, method, "Will multiply 122 by \"7\" and return 854.")
+
+	expected = "natspec.js error setting expression: (anonymous): Line 1:41 Unexpected number"
+
+	if err == nil {
+		t.Errorf("expected error, got nothing (notice: '%v')", err, notice)
+	} else {
+		if err.Error() != expected {
+			t.Errorf("expected error '%s' got '%v' (notice: '%v')", expected, err, notice)
+		}
+	}
+
+	// https://github.com/ethereum/natspec.js/issues/1
+	badDesc := "Will multiply `e` by 7 and return `a * 7`."
+	notice, err = ns.Notice(tx, abi, method, badDesc)
+
+	expected = "natspec.js error evaluating expression: Error: Natspec evaluation failed, wrong input params"
+
+	if err == nil {
+		t.Errorf("expected error, got nothing (notice: '%v')", notice)
+	} else {
+		if err.Error() != expected {
+			t.Errorf("expected error '%s' got '%v' (notice: '%v')", expected, err, notice)
+		}
+	}
+
+	notice, err = ns.Notice(tx, abi, "missing_method", desc)
+
+	expected = "natspec.js error evaluating expression: Error: Natspec evaluation failed, method does not exist"
+
+	if err == nil {
+		t.Errorf("expected error, got nothing (notice: '%v')", notice)
+	} else {
+		if err.Error() != expected {
+			t.Errorf("expected error '%s' got '%v' (notice: '%v')", expected, err, notice)
+		}
+	}
+
+}