1 files changed, 53 insertions, 0 deletions
diff --git a/packages/utils/src/abi_encoder/evm_data_types/bool.ts b/packages/utils/src/abi_encoder/evm_data_types/bool.ts
new file mode 100644
index 000000000..d713d5a94
--- /dev/null
+++ b/packages/utils/src/abi_encoder/evm_data_types/bool.ts
@@ -0,0 +1,53 @@
+import { DataItem, SolidityTypes } from 'ethereum-types';
+import * as ethUtil from 'ethereumjs-util';
+import * as _ from 'lodash';
+
+import { BigNumber } from '../../configured_bignumber';
+import { DataTypeFactory } from '../abstract_data_types/interfaces';
+import { AbstractBlobDataType } from '../abstract_data_types/types/blob';
+import { RawCalldata } from '../calldata/raw_calldata';
+import { constants } from '../utils/constants';
+
+export class BoolDataType extends AbstractBlobDataType {
+    private static readonly _SIZE_KNOWN_AT_COMPILE_TIME: boolean = true;
+
+    public static matchType(type: string): boolean {
+        return type === SolidityTypes.Bool;
+    }
+
+    public constructor(dataItem: DataItem, dataTypeFactory: DataTypeFactory) {
+        super(dataItem, dataTypeFactory, BoolDataType._SIZE_KNOWN_AT_COMPILE_TIME);
+        if (!BoolDataType.matchType(dataItem.type)) {
+            throw new Error(`Tried to instantiate Bool with bad input: ${dataItem}`);
+        }
+    }
+
+    // Disable prefer-function-over-method for inherited abstract methods.
+    /* tslint:disable prefer-function-over-method */
+    public encodeValue(value: boolean): Buffer {
+        const encodedValue = value ? '0x1' : '0x0';
+        const encodedValueBuf = ethUtil.setLengthLeft(
+            ethUtil.toBuffer(encodedValue),
+            constants.EVM_WORD_WIDTH_IN_BYTES,
+        );
+        return encodedValueBuf;
+    }
+
+    public decodeValue(calldata: RawCalldata): boolean {
+        const valueBuf = calldata.popWord();
+        const valueHex = ethUtil.bufferToHex(valueBuf);
+        const valueNumber = new BigNumber(valueHex, constants.HEX_BASE);
+        if (!(valueNumber.equals(0) || valueNumber.equals(1))) {
+            throw new Error(`Failed to decode boolean. Expected 0x0 or 0x1, got ${valueHex}`);
+        }
+        /* tslint:disable boolean-naming */
+        const value: boolean = !valueNumber.equals(0);
+        /* tslint:enable boolean-naming */
+        return value;
+    }
+
+    public getSignature(): string {
+        return SolidityTypes.Bool;
+    }
+    /* tslint:enable prefer-function-over-method */
+}