Require ABI filepath for watching a contract

pkg/geth/abi.go

@@ -14,14 +14,21 @@ var (
 )
 
 func ParseAbiFile(abiFilePath string) (abi.ABI, error) {
-	filesBytes, err := ioutil.ReadFile(abiFilePath)
+	abiString, err := ReadAbiFile(abiFilePath)
 	if err != nil {
 		return abi.ABI{}, ErrMissingAbiFile
 	}
-	abiString := string(filesBytes)
 	parsedAbi, err := abi.JSON(strings.NewReader(abiString))
 	if err != nil {
 		return abi.ABI{}, ErrInvalidAbiFile
 	}
 	return parsedAbi, nil
 }
+
+func ReadAbiFile(abiFilePath string) (string, error) {
+	filesBytes, err := ioutil.ReadFile(abiFilePath)
+	if err != nil {
+		return "", ErrMissingAbiFile
+	}
+	return string(filesBytes), nil
+}

pkg/geth/abi_test.go

@@ -21,6 +21,15 @@ var _ = Describe("Reading ABI files", func() {
 		Expect(err).To(BeNil())
 	})
 
+	It("reads the contents of a valid ABI file", func() {
+		path := filepath.Join(cfg.ProjectRoot(), "pkg", "geth", "testing", "valid_abi.json")
+
+		contractAbi, err := geth.ReadAbiFile(path)
+
+		Expect(contractAbi).To(Equal("[{\"foo\": \"bar\"}]"))
+		Expect(err).To(BeNil())
+	})
+
 	It("returns an error when the file does not exist", func() {
 		path := filepath.Join(cfg.ProjectRoot(), "pkg", "geth", "testing", "missing_abi.json")
 

pkg/geth/testing/valid_abi.json

@@ -1 +1 @@
-[{"constant":true,"inputs":[],"name":"mintingFinished","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"name","outputs":[{"name":"","type":"string"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_spender","type":"address"},{"name":"_value","type":"uint256"}],"name":"approve","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"totalSupply","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_from","type":"address"},{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transferFrom","outputs":[],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"decimals","outputs":[{"name":"","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"unpause","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_amount","type":"uint256"}],"name":"mint","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"paused","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"}],"name":"balanceOf","outputs":[{"name":"balance","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"finishMinting","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":false,"inputs":[],"name":"pause","outputs":[{"name":"","type":"bool"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"owner","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[],"name":"symbol","outputs":[{"name":"","type":"string"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_value","type":"uint256"}],"name":"transfer","outputs":[],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"_to","type":"address"},{"name":"_amount","type":"uint256"},{"name":"_releaseTime","type":"uint256"}],"name":"mintTimelocked","outputs":[{"name":"","type":"address"}],"payable":false,"type":"function"},{"constant":true,"inputs":[{"name":"_owner","type":"address"},{"name":"_spender","type":"address"}],"name":"allowance","outputs":[{"name":"remaining","type":"uint256"}],"payable":false,"type":"function"},{"constant":false,"inputs":[{"name":"newOwner","type":"address"}],"name":"transferOwnership","outputs":[],"payable":false,"type":"function"},{"anonymous":false,"inputs":[{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Mint","type":"event"},{"anonymous":false,"inputs":[],"name":"MintFinished","type":"event"},{"anonymous":false,"inputs":[],"name":"Pause","type":"event"},{"anonymous":false,"inputs":[],"name":"Unpause","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"owner","type":"address"},{"indexed":true,"name":"spender","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Approval","type":"event"},{"anonymous":false,"inputs":[{"indexed":true,"name":"from","type":"address"},{"indexed":true,"name":"to","type":"address"},{"indexed":false,"name":"value","type":"uint256"}],"name":"Transfer","type":"event"}]
+[{"foo": "bar"}]