Split EVM data types and factory into separate files

1 files changed, 51 insertions, 0 deletions

diff --git a/packages/utils/src/abi_encoder/evm_data_types/address.ts b/packages/utils/src/abi_encoder/evm_data_types/address.ts
new file mode 100644
index 000000000..4bd992cab
--- /dev/null
+++ b/packages/utils/src/abi_encoder/evm_data_types/address.ts
@@ -0,0 +1,51 @@
+/* tslint:disable prefer-function-over-method */
+import { DataItem } from 'ethereum-types';
+import * as ethUtil from 'ethereumjs-util';
+import * as _ from 'lodash';
+
+import { RawCalldata } from '../calldata';
+import * as Constants from '../constants';
+import { DataTypeFactory, PayloadDataType } from '../data_type';
+
+export class Address extends PayloadDataType {
+    public static ERROR_MESSAGE_ADDRESS_MUST_START_WITH_0X = "Address must start with '0x'";
+    public static ERROR_MESSAGE_ADDRESS_MUST_BE_20_BYTES = 'Address must be 20 bytes';
+    private static readonly _SIZE_KNOWN_AT_COMPILE_TIME: boolean = true;
+    private static readonly _ADDRESS_SIZE_IN_BYTES = 20;
+    private static readonly _DECODED_ADDRESS_OFFSET_IN_BYTES = Constants.EVM_WORD_WIDTH_IN_BYTES -
+        Address._ADDRESS_SIZE_IN_BYTES;
+
+    public static matchType(type: string): boolean {
+        return type === 'address';
+    }
+
+    public constructor(dataItem: DataItem, dataTypeFactory: DataTypeFactory) {
+        super(dataItem, dataTypeFactory, Address._SIZE_KNOWN_AT_COMPILE_TIME);
+        if (!Address.matchType(dataItem.type)) {
+            throw new Error(`Tried to instantiate Address with bad input: ${dataItem}`);
+        }
+    }
+
+    public getSignature(): string {
+        return 'address';
+    }
+
+    public encodeValue(value: string): Buffer {
+        if (!value.startsWith('0x')) {
+            throw new Error(Address.ERROR_MESSAGE_ADDRESS_MUST_START_WITH_0X);
+        }
+        const valueAsBuffer = ethUtil.toBuffer(value);
+        if (valueAsBuffer.byteLength !== Address._ADDRESS_SIZE_IN_BYTES) {
+            throw new Error(Address.ERROR_MESSAGE_ADDRESS_MUST_BE_20_BYTES);
+        }
+        const encodedValueBuf = ethUtil.setLengthLeft(valueAsBuffer, Constants.EVM_WORD_WIDTH_IN_BYTES);
+        return encodedValueBuf;
+    }
+
+    public decodeValue(calldata: RawCalldata): string {
+        const paddedValueBuf = calldata.popWord();
+        const valueBuf = paddedValueBuf.slice(Address._DECODED_ADDRESS_OFFSET_IN_BYTES);
+        const value = ethUtil.bufferToHex(valueBuf);
+        return value;
+    }
+}