Export class instead of function

5 files changed, 529 insertions, 526 deletions

diff --git a/packages/sol-doc/src/cli.ts b/packages/sol-doc/src/cli.ts
index eb0f00bf6..04956510e 100644
--- a/packages/sol-doc/src/cli.ts
+++ b/packages/sol-doc/src/cli.ts
@@ -3,7 +3,7 @@ import * as yargs from 'yargs';
 
 import { logUtils } from '@0xproject/utils';
 
-import { generateSolDocAsync } from './solidity_doc_generator';
+import { SolDoc } from './sol_doc';
 
 const JSON_TAB_WIDTH = 4;
 
@@ -20,7 +20,20 @@ const JSON_TAB_WIDTH = 4;
         .demandOption('contracts-dir')
         .array('contracts')
         .help().argv;
-    const doc = await generateSolDocAsync(argv.contractsDir, argv.contracts);
+    // Unforunately, the only way to currently retrieve the declared structs within Solidity contracts
+    // is to tease them out of the params/return values included in the ABI. These structures do
+    // not include the structs actual name, so we need a mapping to assign the proper name to a
+    // struct. If the name is not in this mapping, the structs name will default to the param/return value
+    // name (which mostly coincide).
+    const customTypeHashToName: { [hash: string]: string } = {
+        '52d4a768701076c7bac06e386e430883975eb398732eccba797fd09dd064a60e': 'Order',
+        '46f7e8c4d144d11a72ce5338458ea37b933500d7a65e740cbca6d16e350eaa48': 'FillResult',
+        c22239cf0d29df1e6cf1be54f21692a8c0b3a48b9367540d4ffff4608b331ce9: 'OrderInfo',
+        c21e9ff31a30941c22e1cb43752114bb467c34dea58947f98966c9030fc8e4a9: 'TraderInfo',
+        '07c2bddc165e0b5005e6244dd4a9771fa61c78c4f42abd687d57567b0768136c': 'MatchedFillResults',
+    };
+    const solDoc = new SolDoc();
+    const doc = await solDoc.generateSolDocAsync(argv.contractsDir, argv.contracts, customTypeHashToName);
     process.stdout.write(JSON.stringify(doc, null, JSON_TAB_WIDTH));
 })().catch(err => {
     logUtils.warn(err);
diff --git a/packages/sol-doc/src/index.ts b/packages/sol-doc/src/index.ts
index 03f3c9de6..521668cc8 100644
--- a/packages/sol-doc/src/index.ts
+++ b/packages/sol-doc/src/index.ts
@@ -1 +1 @@
-export { generateSolDocAsync } from './solidity_doc_generator';
+export { SolDoc } from './sol_doc';
diff --git a/packages/sol-doc/src/sol_doc.ts b/packages/sol-doc/src/sol_doc.ts
new file mode 100644
index 000000000..4b7cbe77c
--- /dev/null
+++ b/packages/sol-doc/src/sol_doc.ts
@@ -0,0 +1,500 @@
+import * as path from 'path';
+
+import {
+    AbiDefinition,
+    ConstructorAbi,
+    DataItem,
+    DevdocOutput,
+    EventAbi,
+    EventParameter,
+    FallbackAbi,
+    MethodAbi,
+    StandardContractOutput,
+} from 'ethereum-types';
+import ethUtil = require('ethereumjs-util');
+import * as _ from 'lodash';
+
+import { Compiler, CompilerOptions } from '@0xproject/sol-compiler';
+import {
+    CustomType,
+    CustomTypeChild,
+    DocAgnosticFormat,
+    DocSection,
+    Event,
+    EventArg,
+    ObjectMap,
+    Parameter,
+    SolidityMethod,
+    Type,
+    TypeDocTypes,
+} from '@0xproject/types';
+
+export class SolDoc {
+    private _customTypeHashToName: ObjectMap<string> | undefined;
+    private static _genEventDoc(abiDefinition: EventAbi): Event {
+        const eventDoc: Event = {
+            name: abiDefinition.name,
+            eventArgs: SolDoc._genEventArgsDoc(abiDefinition.inputs),
+        };
+        return eventDoc;
+    }
+    private static _devdocMethodDetailsIfExist(
+        methodSignature: string,
+        devdocIfExists: DevdocOutput | undefined,
+    ): string | undefined {
+        let details;
+        if (!_.isUndefined(devdocIfExists)) {
+            const devdocMethodsIfExist = devdocIfExists.methods;
+            if (!_.isUndefined(devdocMethodsIfExist)) {
+                const devdocMethodIfExists = devdocMethodsIfExist[methodSignature];
+                if (!_.isUndefined(devdocMethodIfExists)) {
+                    const devdocMethodDetailsIfExist = devdocMethodIfExists.details;
+                    if (!_.isUndefined(devdocMethodDetailsIfExist)) {
+                        details = devdocMethodDetailsIfExist;
+                    }
+                }
+            }
+        }
+        return details;
+    }
+    private static _genFallbackDoc(
+        abiDefinition: FallbackAbi,
+        devdocIfExists: DevdocOutput | undefined,
+    ): SolidityMethod {
+        const methodSignature = `()`;
+        const comment = SolDoc._devdocMethodDetailsIfExist(methodSignature, devdocIfExists);
+
+        const returnComment =
+            _.isUndefined(devdocIfExists) || _.isUndefined(devdocIfExists.methods[methodSignature])
+                ? undefined
+                : devdocIfExists.methods[methodSignature].return;
+
+        const methodDoc: SolidityMethod = {
+            isConstructor: false,
+            name: 'fallback',
+            callPath: '',
+            parameters: [],
+            returnType: { name: 'void', typeDocType: TypeDocTypes.Intrinsic },
+            returnComment,
+            isConstant: true,
+            isPayable: abiDefinition.payable,
+            isFallback: true,
+            comment: _.isEmpty(comment)
+                ? 'The fallback function. It is executed on a call to the contract if none of the other functions match the given public identifier (or if no data was supplied at all).'
+                : comment,
+        };
+        return methodDoc;
+    }
+    private static _genEventArgsDoc(args: EventParameter[]): EventArg[] {
+        const eventArgsDoc: EventArg[] = [];
+
+        for (const arg of args) {
+            const name = arg.name;
+
+            const type: Type = {
+                name: arg.type,
+                typeDocType: TypeDocTypes.Intrinsic,
+            };
+
+            const eventArgDoc: EventArg = {
+                isIndexed: arg.indexed,
+                name,
+                type,
+            };
+
+            eventArgsDoc.push(eventArgDoc);
+        }
+        return eventArgsDoc;
+    }
+    private static _dedupStructs(customTypes: CustomType[]): CustomType[] {
+        const uniqueCustomTypes: CustomType[] = [];
+        const seenTypes: { [hash: string]: boolean } = {};
+        _.each(customTypes, customType => {
+            const hash = SolDoc._generateCustomTypeHash(customType);
+            if (!seenTypes[hash]) {
+                uniqueCustomTypes.push(customType);
+                seenTypes[hash] = true;
+            }
+        });
+        return uniqueCustomTypes;
+    }
+    private static _capitalize(text: string): string {
+        return `${text.charAt(0).toUpperCase()}${text.slice(1)}`;
+    }
+    private static _generateCustomTypeHash(customType: CustomType): string {
+        const customTypeWithoutName = _.cloneDeep(customType);
+        delete customTypeWithoutName.name;
+        const customTypeWithoutNameStr = JSON.stringify(customTypeWithoutName);
+        const hash = ethUtil.sha256(customTypeWithoutNameStr).toString('hex');
+        return hash;
+    }
+    private static _makeCompilerOptions(contractsDir: string, contractsToCompile?: string[]): CompilerOptions {
+        const compilerOptions: CompilerOptions = {
+            contractsDir,
+            contracts: '*',
+            compilerSettings: {
+                outputSelection: {
+                    ['*']: {
+                        ['*']: ['abi', 'devdoc'],
+                    },
+                },
+            },
+        };
+
+        const shouldOverrideCatchAllContractsConfig =
+            !_.isUndefined(contractsToCompile) && contractsToCompile.length > 0;
+        if (shouldOverrideCatchAllContractsConfig) {
+            compilerOptions.contracts = contractsToCompile;
+        }
+
+        return compilerOptions;
+    }
+    /**
+     * Invoke the Solidity compiler and transform its ABI and devdoc outputs into a
+     * JSON format easily consumed by documentation rendering tools.
+     * @param contractsToDocument list of contracts for which to generate doc objects
+     * @param contractsDir the directory in which to find the `contractsToCompile` as well as their dependencies.
+     * @return doc object for use with documentation generation tools.
+     */
+    public async generateSolDocAsync(
+        contractsDir: string,
+        contractsToDocument?: string[],
+        customTypeHashToName?: ObjectMap<string>,
+    ): Promise<DocAgnosticFormat> {
+        this._customTypeHashToName = customTypeHashToName;
+        const docWithDependencies: DocAgnosticFormat = {};
+        const compilerOptions = SolDoc._makeCompilerOptions(contractsDir, contractsToDocument);
+        const compiler = new Compiler(compilerOptions);
+        const compilerOutputs = await compiler.getCompilerOutputsAsync();
+        let structs: CustomType[] = [];
+        for (const compilerOutput of compilerOutputs) {
+            const contractFileNames = _.keys(compilerOutput.contracts);
+            for (const contractFileName of contractFileNames) {
+                const contractNameToOutput = compilerOutput.contracts[contractFileName];
+
+                const contractNames = _.keys(contractNameToOutput);
+                for (const contractName of contractNames) {
+                    const compiledContract = contractNameToOutput[contractName];
+                    if (_.isUndefined(compiledContract.abi)) {
+                        throw new Error('compiled contract did not contain ABI output');
+                    }
+                    docWithDependencies[contractName] = this._genDocSection(compiledContract, contractName);
+                    structs = [...structs, ...this._extractStructs(compiledContract)];
+                }
+            }
+        }
+        structs = SolDoc._dedupStructs(structs);
+        structs = this._overwriteStructNames(structs);
+
+        let doc: DocAgnosticFormat = {};
+        if (_.isUndefined(contractsToDocument) || contractsToDocument.length === 0) {
+            doc = docWithDependencies;
+        } else {
+            for (const contractToDocument of contractsToDocument) {
+                const contractBasename = path.basename(contractToDocument);
+                const contractName =
+                    contractBasename.lastIndexOf('.sol') === -1
+                        ? contractBasename
+                        : contractBasename.substring(0, contractBasename.lastIndexOf('.sol'));
+                doc[contractName] = docWithDependencies[contractName];
+            }
+        }
+
+        if (structs.length > 0) {
+            doc.structs = {
+                comment: '',
+                constructors: [],
+                methods: [],
+                properties: [],
+                types: structs,
+                functions: [],
+                events: [],
+            };
+        }
+
+        delete this._customTypeHashToName; // Clean up instance state
+        return doc;
+    }
+    private _getCustomTypeFromDataItem(inputOrOutput: DataItem): CustomType {
+        const customType: CustomType = {
+            name: _.capitalize(inputOrOutput.name),
+            kindString: 'Interface',
+            children: [],
+        };
+        _.each(inputOrOutput.components, (component: DataItem) => {
+            const childType = this._getTypeFromDataItem(component);
+            const customTypeChild = {
+                name: component.name,
+                type: childType,
+            };
+            // (fabio): Not sure why this type casting is necessary. Seems TS doesn't
+            // deduce that `customType.children` cannot be undefined anymore after being
+            // set to `[]` above.
+            (customType.children as CustomTypeChild[]).push(customTypeChild);
+        });
+        return customType;
+    }
+    private _getNameFromDataItemIfExists(dataItem: DataItem): string | undefined {
+        if (_.isUndefined(dataItem.components)) {
+            return undefined;
+        }
+        const customType = this._getCustomTypeFromDataItem(dataItem);
+        const hash = SolDoc._generateCustomTypeHash(customType);
+        if (_.isUndefined(this._customTypeHashToName) || _.isUndefined(this._customTypeHashToName[hash])) {
+            return undefined;
+        }
+        return this._customTypeHashToName[hash];
+    }
+    private _getTypeFromDataItem(dataItem: DataItem): Type {
+        const typeDocType = !_.isUndefined(dataItem.components) ? TypeDocTypes.Reference : TypeDocTypes.Intrinsic;
+        let typeName: string;
+        if (typeDocType === TypeDocTypes.Reference) {
+            const nameIfExists = this._getNameFromDataItemIfExists(dataItem);
+            typeName = _.isUndefined(nameIfExists) ? SolDoc._capitalize(dataItem.name) : nameIfExists;
+        } else {
+            typeName = dataItem.type;
+        }
+
+        const isArrayType = _.endsWith(dataItem.type, '[]');
+        let type: Type;
+        if (isArrayType) {
+            // tslint:disable-next-line:custom-no-magic-numbers
+            typeName = typeDocType === TypeDocTypes.Intrinsic ? typeName.slice(0, -2) : typeName;
+            type = {
+                elementType: { name: typeName, typeDocType },
+                typeDocType: TypeDocTypes.Array,
+                name: '',
+            };
+        } else {
+            type = { name: typeName, typeDocType };
+        }
+        return type;
+    }
+    private _overwriteStructNames(customTypes: CustomType[], customTypeHashToName?: ObjectMap<string>): CustomType[] {
+        if (_.isUndefined(customTypeHashToName)) {
+            return customTypes;
+        }
+        const localCustomTypes = _.cloneDeep(customTypes);
+        _.each(localCustomTypes, customType => {
+            const hash = SolDoc._generateCustomTypeHash(customType);
+            if (!_.isUndefined(this._customTypeHashToName) && !_.isUndefined(this._customTypeHashToName[hash])) {
+                customType.name = this._customTypeHashToName[hash];
+            }
+        });
+        return localCustomTypes;
+    }
+    private _extractStructs(compiledContract: StandardContractOutput): CustomType[] {
+        let customTypes: CustomType[] = [];
+        for (const abiDefinition of compiledContract.abi) {
+            let types: CustomType[] = [];
+            switch (abiDefinition.type) {
+                case 'constructor': {
+                    types = this._getStructsAsCustomTypes(abiDefinition);
+                    break;
+                }
+                case 'function': {
+                    types = this._getStructsAsCustomTypes(abiDefinition);
+                    break;
+                }
+                case 'event':
+                case 'fallback':
+                    // No types exist
+                    break;
+                default:
+                    throw new Error(
+                        `unknown and unsupported AbiDefinition type '${(abiDefinition as AbiDefinition).type}'`,
+                    );
+            }
+            customTypes = [...customTypes, ...types];
+        }
+        return customTypes;
+    }
+    private _genDocSection(compiledContract: StandardContractOutput, contractName: string): DocSection {
+        const docSection: DocSection = {
+            comment: _.isUndefined(compiledContract.devdoc) ? '' : compiledContract.devdoc.title,
+            constructors: [],
+            methods: [],
+            properties: [],
+            types: [],
+            functions: [],
+            events: [],
+        };
+
+        for (const abiDefinition of compiledContract.abi) {
+            switch (abiDefinition.type) {
+                case 'constructor':
+                    docSection.constructors.push(
+                        this._genConstructorDoc(contractName, abiDefinition, compiledContract.devdoc),
+                    );
+                    break;
+                case 'event':
+                    (docSection.events as Event[]).push(SolDoc._genEventDoc(abiDefinition));
+                    // note that we're not sending devdoc to this._genEventDoc().
+                    // that's because the type of the events array doesn't have any fields for documentation!
+                    break;
+                case 'function':
+                    docSection.methods.push(this._genMethodDoc(abiDefinition, compiledContract.devdoc));
+                    break;
+                case 'fallback':
+                    docSection.methods.push(SolDoc._genFallbackDoc(abiDefinition, compiledContract.devdoc));
+                    break;
+                default:
+                    throw new Error(
+                        `unknown and unsupported AbiDefinition type '${(abiDefinition as AbiDefinition).type}'`,
+                    );
+            }
+        }
+
+        return docSection;
+    }
+    private _genConstructorDoc(
+        contractName: string,
+        abiDefinition: ConstructorAbi,
+        devdocIfExists: DevdocOutput | undefined,
+    ): SolidityMethod {
+        const { parameters, methodSignature } = this._genMethodParamsDoc('', abiDefinition.inputs, devdocIfExists);
+
+        const comment = SolDoc._devdocMethodDetailsIfExist(methodSignature, devdocIfExists);
+
+        const constructorDoc: SolidityMethod = {
+            isConstructor: true,
+            name: contractName,
+            callPath: '',
+            parameters,
+            returnType: { name: contractName, typeDocType: TypeDocTypes.Reference }, // sad we have to specify this
+            isConstant: false,
+            isPayable: abiDefinition.payable,
+            comment,
+        };
+
+        return constructorDoc;
+    }
+    private _genMethodDoc(abiDefinition: MethodAbi, devdocIfExists: DevdocOutput | undefined): SolidityMethod {
+        const name = abiDefinition.name;
+        const { parameters, methodSignature } = this._genMethodParamsDoc(name, abiDefinition.inputs, devdocIfExists);
+        const devDocComment = SolDoc._devdocMethodDetailsIfExist(methodSignature, devdocIfExists);
+        const returnType = this._genMethodReturnTypeDoc(abiDefinition.outputs);
+        const returnComment =
+            _.isUndefined(devdocIfExists) || _.isUndefined(devdocIfExists.methods[methodSignature])
+                ? undefined
+                : devdocIfExists.methods[methodSignature].return;
+
+        const hasNoNamedParameters = _.isUndefined(_.find(parameters, p => !_.isEmpty(p.name)));
+        const isGeneratedGetter = hasNoNamedParameters;
+        const comment =
+            _.isEmpty(devDocComment) && isGeneratedGetter
+                ? `This is an auto-generated accessor method of the '${name}' contract instance variable.`
+                : devDocComment;
+        const methodDoc: SolidityMethod = {
+            isConstructor: false,
+            name,
+            callPath: '',
+            parameters,
+            returnType,
+            returnComment,
+            isConstant: abiDefinition.constant,
+            isPayable: abiDefinition.payable,
+            comment,
+        };
+        return methodDoc;
+    }
+    /**
+     * Extract documentation for each method parameter from @param params.
+     */
+    private _genMethodParamsDoc(
+        name: string,
+        abiParams: DataItem[],
+        devdocIfExists: DevdocOutput | undefined,
+    ): { parameters: Parameter[]; methodSignature: string } {
+        const parameters: Parameter[] = [];
+        for (const abiParam of abiParams) {
+            const type = this._getTypeFromDataItem(abiParam);
+
+            const parameter: Parameter = {
+                name: abiParam.name,
+                comment: '<No comment>',
+                isOptional: false, // Unsupported in Solidity, until resolution of https://github.com/ethereum/solidity/issues/232
+                type,
+            };
+            parameters.push(parameter);
+        }
+
+        const methodSignature = `${name}(${abiParams
+            .map(abiParam => {
+                if (!_.startsWith(abiParam.type, 'tuple')) {
+                    return abiParam.type;
+                } else {
+                    // Need to expand tuples:
+                    // E.g: fillOrder(tuple,uint256,bytes) -> fillOrder((address,address,address,address,uint256,uint256,uint256,uint256,uint256,uint256,bytes,bytes),uint256,bytes)
+                    const isArray = _.endsWith(abiParam.type, '[]');
+                    const expandedTypes = _.map(abiParam.components, c => c.type);
+                    const type = `(${expandedTypes.join(',')})${isArray ? '[]' : ''}`;
+                    return type;
+                }
+            })
+            .join(',')})`;
+
+        if (!_.isUndefined(devdocIfExists)) {
+            const devdocMethodIfExists = devdocIfExists.methods[methodSignature];
+            if (!_.isUndefined(devdocMethodIfExists)) {
+                const devdocParamsIfExist = devdocMethodIfExists.params;
+                if (!_.isUndefined(devdocParamsIfExist)) {
+                    for (const parameter of parameters) {
+                        parameter.comment = devdocParamsIfExist[parameter.name];
+                    }
+                }
+            }
+        }
+
+        return { parameters, methodSignature };
+    }
+    private _genMethodReturnTypeDoc(outputs: DataItem[]): Type {
+        let type: Type;
+        if (outputs.length > 1) {
+            type = {
+                name: '',
+                typeDocType: TypeDocTypes.Tuple,
+                tupleElements: [],
+            };
+            for (const output of outputs) {
+                const tupleType = this._getTypeFromDataItem(output);
+                (type.tupleElements as Type[]).push(tupleType);
+            }
+            return type;
+        } else if (outputs.length === 1) {
+            const output = outputs[0];
+            type = this._getTypeFromDataItem(output);
+        } else {
+            type = {
+                name: 'void',
+                typeDocType: TypeDocTypes.Intrinsic,
+            };
+        }
+        return type;
+    }
+    private _getStructsAsCustomTypes(abiDefinition: AbiDefinition): CustomType[] {
+        const customTypes: CustomType[] = [];
+        // We cast to `any` here because we do not know yet if this type of abiDefinition contains
+        // an `input` key
+        if (!_.isUndefined((abiDefinition as any).inputs)) {
+            const methodOrConstructorAbi = abiDefinition as MethodAbi | ConstructorAbi;
+            _.each(methodOrConstructorAbi.inputs, input => {
+                if (!_.isUndefined(input.components)) {
+                    const customType = this._getCustomTypeFromDataItem(input);
+                    customTypes.push(customType);
+                }
+            });
+        }
+        if (!_.isUndefined((abiDefinition as any).outputs)) {
+            const methodAbi = abiDefinition as MethodAbi;
+            _.each(methodAbi.outputs, output => {
+                if (!_.isUndefined(output.components)) {
+                    const customType = this._getCustomTypeFromDataItem(output);
+                    customTypes.push(customType);
+                }
+            });
+        }
+        return customTypes;
+    }
+}
+// tslint:disable:max-file-line-count
diff --git a/packages/sol-doc/src/solidity_doc_generator.ts b/packages/sol-doc/src/solidity_doc_generator.ts
deleted file mode 100644
index 424577411..000000000
--- a/packages/sol-doc/src/solidity_doc_generator.ts
+++ /dev/null
@@ -1,516 +0,0 @@
-import * as path from 'path';
-
-import {
-    AbiDefinition,
-    ConstructorAbi,
-    DataItem,
-    DevdocOutput,
-    EventAbi,
-    EventParameter,
-    FallbackAbi,
-    MethodAbi,
-    StandardContractOutput,
-} from 'ethereum-types';
-import ethUtil = require('ethereumjs-util');
-import * as _ from 'lodash';
-
-import { Compiler, CompilerOptions } from '@0xproject/sol-compiler';
-import {
-    CustomType,
-    CustomTypeChild,
-    DocAgnosticFormat,
-    DocSection,
-    Event,
-    EventArg,
-    Parameter,
-    SolidityMethod,
-    Type,
-    TypeDocTypes,
-} from '@0xproject/types';
-
-// Unforunately, the only way to currently retrieve the declared structs within Solidity contracts
-// is to tease them out of the params/return values included in the ABI. These structures do
-// not include the structs actual name, so we need a mapping to assign the proper name to a
-// struct. If the name is not in this mapping, the structs name will default to the param/return value
-// name (which mostly coincide).
-const customTypeHashToName: { [hash: string]: string } = {
-    '52d4a768701076c7bac06e386e430883975eb398732eccba797fd09dd064a60e': 'Order',
-    '46f7e8c4d144d11a72ce5338458ea37b933500d7a65e740cbca6d16e350eaa48': 'FillResult',
-    c22239cf0d29df1e6cf1be54f21692a8c0b3a48b9367540d4ffff4608b331ce9: 'OrderInfo',
-    c21e9ff31a30941c22e1cb43752114bb467c34dea58947f98966c9030fc8e4a9: 'TraderInfo',
-    '07c2bddc165e0b5005e6244dd4a9771fa61c78c4f42abd687d57567b0768136c': 'MatchedFillResult',
-};
-
-/**
- * Invoke the Solidity compiler and transform its ABI and devdoc outputs into a
- * JSON format easily consumed by documentation rendering tools.
- * @param contractsToDocument list of contracts for which to generate doc objects
- * @param contractsDir the directory in which to find the `contractsToCompile` as well as their dependencies.
- * @return doc object for use with documentation generation tools.
- */
-export async function generateSolDocAsync(
-    contractsDir: string,
-    contractsToDocument?: string[],
-): Promise<DocAgnosticFormat> {
-    const docWithDependencies: DocAgnosticFormat = {};
-    const compilerOptions = _makeCompilerOptions(contractsDir, contractsToDocument);
-    const compiler = new Compiler(compilerOptions);
-    const compilerOutputs = await compiler.getCompilerOutputsAsync();
-    let structs: CustomType[] = [];
-    for (const compilerOutput of compilerOutputs) {
-        const contractFileNames = _.keys(compilerOutput.contracts);
-        for (const contractFileName of contractFileNames) {
-            const contractNameToOutput = compilerOutput.contracts[contractFileName];
-
-            const contractNames = _.keys(contractNameToOutput);
-            for (const contractName of contractNames) {
-                const compiledContract = contractNameToOutput[contractName];
-                if (_.isUndefined(compiledContract.abi)) {
-                    throw new Error('compiled contract did not contain ABI output');
-                }
-                docWithDependencies[contractName] = _genDocSection(compiledContract, contractName);
-                structs = [...structs, ..._extractStructs(compiledContract)];
-            }
-        }
-    }
-    structs = _dedupStructs(structs);
-    structs = _overwriteStructNames(structs);
-
-    let doc: DocAgnosticFormat = {};
-    if (_.isUndefined(contractsToDocument) || contractsToDocument.length === 0) {
-        doc = docWithDependencies;
-    } else {
-        for (const contractToDocument of contractsToDocument) {
-            const contractBasename = path.basename(contractToDocument);
-            const contractName =
-                contractBasename.lastIndexOf('.sol') === -1
-                    ? contractBasename
-                    : contractBasename.substring(0, contractBasename.lastIndexOf('.sol'));
-            doc[contractName] = docWithDependencies[contractName];
-        }
-    }
-
-    if (structs.length > 0) {
-        doc.structs = {
-            comment: '',
-            constructors: [],
-            methods: [],
-            properties: [],
-            types: structs,
-            functions: [],
-            events: [],
-        };
-    }
-
-    return doc;
-}
-
-function _makeCompilerOptions(contractsDir: string, contractsToCompile?: string[]): CompilerOptions {
-    const compilerOptions: CompilerOptions = {
-        contractsDir,
-        contracts: '*',
-        compilerSettings: {
-            outputSelection: {
-                ['*']: {
-                    ['*']: ['abi', 'devdoc'],
-                },
-            },
-        },
-    };
-
-    const shouldOverrideCatchAllContractsConfig = !_.isUndefined(contractsToCompile) && contractsToCompile.length > 0;
-    if (shouldOverrideCatchAllContractsConfig) {
-        compilerOptions.contracts = contractsToCompile;
-    }
-
-    return compilerOptions;
-}
-
-function _extractStructs(compiledContract: StandardContractOutput): CustomType[] {
-    let customTypes: CustomType[] = [];
-    for (const abiDefinition of compiledContract.abi) {
-        let types: CustomType[] = [];
-        switch (abiDefinition.type) {
-            case 'constructor': {
-                types = _getStructsAsCustomTypes(abiDefinition);
-                break;
-            }
-            case 'function': {
-                types = _getStructsAsCustomTypes(abiDefinition);
-                break;
-            }
-            case 'event':
-            case 'fallback':
-                // No types exist
-                break;
-            default:
-                throw new Error(
-                    `unknown and unsupported AbiDefinition type '${(abiDefinition as AbiDefinition).type}'`,
-                );
-        }
-        customTypes = [...customTypes, ...types];
-    }
-    return customTypes;
-}
-
-function _genDocSection(compiledContract: StandardContractOutput, contractName: string): DocSection {
-    const docSection: DocSection = {
-        comment: _.isUndefined(compiledContract.devdoc) ? '' : compiledContract.devdoc.title,
-        constructors: [],
-        methods: [],
-        properties: [],
-        types: [],
-        functions: [],
-        events: [],
-    };
-
-    for (const abiDefinition of compiledContract.abi) {
-        switch (abiDefinition.type) {
-            case 'constructor':
-                docSection.constructors.push(_genConstructorDoc(contractName, abiDefinition, compiledContract.devdoc));
-                break;
-            case 'event':
-                (docSection.events as Event[]).push(_genEventDoc(abiDefinition));
-                // note that we're not sending devdoc to _genEventDoc().
-                // that's because the type of the events array doesn't have any fields for documentation!
-                break;
-            case 'function':
-                docSection.methods.push(_genMethodDoc(abiDefinition, compiledContract.devdoc));
-                break;
-            case 'fallback':
-                docSection.methods.push(_genFallbackDoc(abiDefinition, compiledContract.devdoc));
-                break;
-            default:
-                throw new Error(
-                    `unknown and unsupported AbiDefinition type '${(abiDefinition as AbiDefinition).type}'`,
-                );
-        }
-    }
-
-    return docSection;
-}
-
-function _genConstructorDoc(
-    contractName: string,
-    abiDefinition: ConstructorAbi,
-    devdocIfExists: DevdocOutput | undefined,
-): SolidityMethod {
-    const { parameters, methodSignature } = _genMethodParamsDoc('', abiDefinition.inputs, devdocIfExists);
-
-    const comment = _devdocMethodDetailsIfExist(methodSignature, devdocIfExists);
-
-    const constructorDoc: SolidityMethod = {
-        isConstructor: true,
-        name: contractName,
-        callPath: '',
-        parameters,
-        returnType: { name: contractName, typeDocType: TypeDocTypes.Reference }, // sad we have to specify this
-        isConstant: false,
-        isPayable: abiDefinition.payable,
-        comment,
-    };
-
-    return constructorDoc;
-}
-
-function _devdocMethodDetailsIfExist(
-    methodSignature: string,
-    devdocIfExists: DevdocOutput | undefined,
-): string | undefined {
-    let details;
-    if (!_.isUndefined(devdocIfExists)) {
-        const devdocMethodsIfExist = devdocIfExists.methods;
-        if (!_.isUndefined(devdocMethodsIfExist)) {
-            const devdocMethodIfExists = devdocMethodsIfExist[methodSignature];
-            if (!_.isUndefined(devdocMethodIfExists)) {
-                const devdocMethodDetailsIfExist = devdocMethodIfExists.details;
-                if (!_.isUndefined(devdocMethodDetailsIfExist)) {
-                    details = devdocMethodDetailsIfExist;
-                }
-            }
-        }
-    }
-    return details;
-}
-
-function _genFallbackDoc(abiDefinition: FallbackAbi, devdocIfExists: DevdocOutput | undefined): SolidityMethod {
-    const methodSignature = `()`;
-    const comment = _devdocMethodDetailsIfExist(methodSignature, devdocIfExists);
-
-    const returnComment =
-        _.isUndefined(devdocIfExists) || _.isUndefined(devdocIfExists.methods[methodSignature])
-            ? undefined
-            : devdocIfExists.methods[methodSignature].return;
-
-    const methodDoc: SolidityMethod = {
-        isConstructor: false,
-        name: 'fallback',
-        callPath: '',
-        parameters: [],
-        returnType: { name: 'void', typeDocType: TypeDocTypes.Intrinsic },
-        returnComment,
-        isConstant: true,
-        isPayable: abiDefinition.payable,
-        isFallback: true,
-        comment: _.isEmpty(comment)
-            ? 'The default fallback function. It is executed on a call to the contract if none of the other functions match the given function identifier (or if no data was supplied at all).'
-            : comment,
-    };
-    return methodDoc;
-}
-
-function _genMethodDoc(abiDefinition: MethodAbi, devdocIfExists: DevdocOutput | undefined): SolidityMethod {
-    const name = abiDefinition.name;
-    const { parameters, methodSignature } = _genMethodParamsDoc(name, abiDefinition.inputs, devdocIfExists);
-    const devDocComment = _devdocMethodDetailsIfExist(methodSignature, devdocIfExists);
-    const returnType = _genMethodReturnTypeDoc(abiDefinition.outputs);
-    const returnComment =
-        _.isUndefined(devdocIfExists) || _.isUndefined(devdocIfExists.methods[methodSignature])
-            ? undefined
-            : devdocIfExists.methods[methodSignature].return;
-
-    const hasNoNamedParameters = _.isUndefined(_.find(parameters, p => !_.isEmpty(p.name)));
-    const isGeneratedGetter = hasNoNamedParameters;
-    const comment =
-        _.isEmpty(devDocComment) && isGeneratedGetter
-            ? `This is an auto-generated accessor method of the '${name}' contract instance variable.`
-            : devDocComment;
-    const methodDoc: SolidityMethod = {
-        isConstructor: false,
-        name,
-        callPath: '',
-        parameters,
-        returnType,
-        returnComment,
-        isConstant: abiDefinition.constant,
-        isPayable: abiDefinition.payable,
-        comment,
-    };
-    return methodDoc;
-}
-
-function _genEventDoc(abiDefinition: EventAbi): Event {
-    const eventDoc: Event = {
-        name: abiDefinition.name,
-        eventArgs: _genEventArgsDoc(abiDefinition.inputs, undefined),
-    };
-    return eventDoc;
-}
-
-function _genEventArgsDoc(args: EventParameter[], devdocIfExists: DevdocOutput | undefined): EventArg[] {
-    const eventArgsDoc: EventArg[] = [];
-
-    for (const arg of args) {
-        const name = arg.name;
-
-        const type: Type = {
-            name: arg.type,
-            typeDocType: TypeDocTypes.Intrinsic,
-        };
-
-        const eventArgDoc: EventArg = {
-            isIndexed: arg.indexed,
-            name,
-            type,
-        };
-
-        eventArgsDoc.push(eventArgDoc);
-    }
-    return eventArgsDoc;
-}
-
-/**
- * Extract documentation for each method parameter from @param params.
- */
-function _genMethodParamsDoc(
-    name: string,
-    abiParams: DataItem[],
-    devdocIfExists: DevdocOutput | undefined,
-): { parameters: Parameter[]; methodSignature: string } {
-    const parameters: Parameter[] = [];
-    for (const abiParam of abiParams) {
-        const type = _getTypeFromDataItem(abiParam);
-
-        const parameter: Parameter = {
-            name: abiParam.name,
-            comment: '<No comment>',
-            isOptional: false, // Unsupported in Solidity, until resolution of https://github.com/ethereum/solidity/issues/232
-            type,
-        };
-        parameters.push(parameter);
-    }
-
-    const methodSignature = `${name}(${abiParams
-        .map(abiParam => {
-            if (!_.startsWith(abiParam.type, 'tuple')) {
-                return abiParam.type;
-            } else {
-                // Need to expand tuples:
-                // E.g: fillOrder(tuple,uint256,bytes) -> fillOrder((address,address,address,address,uint256,uint256,uint256,uint256,uint256,uint256,bytes,bytes),uint256,bytes)
-                const isArray = _.endsWith(abiParam.type, '[]');
-                const expandedTypes = _.map(abiParam.components, c => c.type);
-                const type = `(${expandedTypes.join(',')})${isArray ? '[]' : ''}`;
-                return type;
-            }
-        })
-        .join(',')})`;
-
-    if (!_.isUndefined(devdocIfExists)) {
-        const devdocMethodIfExists = devdocIfExists.methods[methodSignature];
-        if (!_.isUndefined(devdocMethodIfExists)) {
-            const devdocParamsIfExist = devdocMethodIfExists.params;
-            if (!_.isUndefined(devdocParamsIfExist)) {
-                for (const parameter of parameters) {
-                    parameter.comment = devdocParamsIfExist[parameter.name];
-                }
-            }
-        }
-    }
-
-    return { parameters, methodSignature };
-}
-
-function _genMethodReturnTypeDoc(outputs: DataItem[]): Type {
-    if (outputs.length > 1) {
-        const type: Type = {
-            name: '',
-            typeDocType: TypeDocTypes.Tuple,
-            tupleElements: [],
-        };
-        for (const output of outputs) {
-            const tupleType = _getTypeFromDataItem(output);
-            (type.tupleElements as Type[]).push(tupleType);
-        }
-        return type;
-    } else if (outputs.length === 1) {
-        const output = outputs[0];
-        const type = _getTypeFromDataItem(output);
-        return type;
-    } else {
-        const type: Type = {
-            name: 'void',
-            typeDocType: TypeDocTypes.Intrinsic,
-        };
-        return type;
-    }
-}
-
-function _capitalize(text: string): string {
-    return `${text.charAt(0).toUpperCase()}${text.slice(1)}`;
-}
-
-function _dedupStructs(customTypes: CustomType[]): CustomType[] {
-    const uniqueCustomTypes: CustomType[] = [];
-    const seenTypes: { [hash: string]: boolean } = {};
-    _.each(customTypes, customType => {
-        const hash = _generateCustomTypeHash(customType);
-        if (!seenTypes[hash]) {
-            uniqueCustomTypes.push(customType);
-            seenTypes[hash] = true;
-        }
-    });
-    return uniqueCustomTypes;
-}
-
-function _overwriteStructNames(customTypes: CustomType[]): CustomType[] {
-    const localCustomTypes = _.cloneDeep(customTypes);
-    _.each(localCustomTypes, customType => {
-        const hash = _generateCustomTypeHash(customType);
-        if (!_.isUndefined(customTypeHashToName[hash])) {
-            customType.name = customTypeHashToName[hash];
-        }
-    });
-    return localCustomTypes;
-}
-
-function _generateCustomTypeHash(customType: CustomType): string {
-    const customTypeWithoutName = _.cloneDeep(customType);
-    delete customTypeWithoutName.name;
-    const customTypeWithoutNameStr = JSON.stringify(customTypeWithoutName);
-    const hash = ethUtil.sha256(customTypeWithoutNameStr).toString('hex');
-    return hash;
-}
-
-function _getStructsAsCustomTypes(abiDefinition: AbiDefinition): CustomType[] {
-    const customTypes: CustomType[] = [];
-    // We cast to `any` here because we do not know yet if this type of abiDefinition contains
-    // an `input` key
-    if (!_.isUndefined((abiDefinition as any).inputs)) {
-        const methodOrConstructorAbi = abiDefinition as MethodAbi | ConstructorAbi;
-        _.each(methodOrConstructorAbi.inputs, input => {
-            if (!_.isUndefined(input.components)) {
-                const customType = _getCustomTypeFromDataItem(input);
-                customTypes.push(customType);
-            }
-        });
-    }
-    if (!_.isUndefined((abiDefinition as any).outputs)) {
-        const methodAbi = abiDefinition as MethodAbi;
-        _.each(methodAbi.outputs, output => {
-            if (!_.isUndefined(output.components)) {
-                const customType = _getCustomTypeFromDataItem(output);
-                customTypes.push(customType);
-            }
-        });
-    }
-    return customTypes;
-}
-
-function _getCustomTypeFromDataItem(inputOrOutput: DataItem): CustomType {
-    const customType: CustomType = {
-        name: _.capitalize(inputOrOutput.name),
-        kindString: 'Interface',
-        children: [],
-    };
-    _.each(inputOrOutput.components, (component: DataItem) => {
-        const childType = _getTypeFromDataItem(component);
-        const customTypeChild = {
-            name: component.name,
-            type: childType,
-        };
-        // (fabio): Not sure why this type casting is necessary. Seems TS doesn't
-        // deduce that `customType.children` cannot be undefined anymore after being
-        // set to `[]` above.
-        (customType.children as CustomTypeChild[]).push(customTypeChild);
-    });
-    return customType;
-}
-
-function _getNameFromDataItemIfExists(dataItem: DataItem): string | undefined {
-    if (_.isUndefined(dataItem.components)) {
-        return undefined;
-    }
-    const customType = _getCustomTypeFromDataItem(dataItem);
-    const hash = _generateCustomTypeHash(customType);
-    if (_.isUndefined(customTypeHashToName[hash])) {
-        return undefined;
-    }
-    return customTypeHashToName[hash];
-}
-
-function _getTypeFromDataItem(dataItem: DataItem): Type {
-    const typeDocType = !_.isUndefined(dataItem.components) ? TypeDocTypes.Reference : TypeDocTypes.Intrinsic;
-    let typeName: string;
-    if (typeDocType === TypeDocTypes.Reference) {
-        const nameIfExists = _getNameFromDataItemIfExists(dataItem);
-        typeName = _.isUndefined(nameIfExists) ? _capitalize(dataItem.name) : nameIfExists;
-    } else {
-        typeName = dataItem.type;
-    }
-
-    const isArrayType = _.endsWith(dataItem.type, '[]');
-    let type: Type;
-    if (isArrayType) {
-        // tslint:disable-next-line:custom-no-magic-numbers
-        typeName = typeDocType === TypeDocTypes.Intrinsic ? typeName.slice(0, -2) : typeName;
-        type = {
-            elementType: { name: typeName, typeDocType },
-            typeDocType: TypeDocTypes.Array,
-            name: '',
-        };
-    } else {
-        type = { name: typeName, typeDocType };
-    }
-    return type;
-}
-// tslint:disable:max-file-line-count
diff --git a/packages/sol-doc/test/solidity_doc_generator_test.ts b/packages/sol-doc/test/solidity_doc_generator_test.ts
index c780d3d31..ba08ebd00 100644
--- a/packages/sol-doc/test/solidity_doc_generator_test.ts
+++ b/packages/sol-doc/test/solidity_doc_generator_test.ts
@@ -5,16 +5,20 @@ import 'mocha';
 
 import { DocAgnosticFormat, Event, SolidityMethod } from '@0xproject/types';
 
-import { generateSolDocAsync } from '../src/solidity_doc_generator';
+import { SolDoc } from '../src/sol_doc';
 
 import { chaiSetup } from './util/chai_setup';
 
 chaiSetup.configure();
 const expect = chai.expect;
+let solDoc: SolDoc;
 
 describe('#SolidityDocGenerator', () => {
+    before(() => {
+        solDoc = new SolDoc();
+    });
     it('should generate a doc object that matches the devdoc-free TokenTransferProxy fixture', async () => {
-        const doc = await generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, [
+        const doc = await solDoc.generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, [
             'TokenTransferProxyNoDevdoc',
         ]);
         expect(doc).to.not.be.undefined();
@@ -22,8 +26,8 @@ describe('#SolidityDocGenerator', () => {
         verifyTokenTransferProxyABIIsDocumented(doc, 'TokenTransferProxyNoDevdoc');
     });
     const docPromises: Array<Promise<DocAgnosticFormat>> = [
-        generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`),
-        generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, []),
+        solDoc.generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`),
+        solDoc.generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, []),
     ];
     docPromises.forEach(docPromise => {
         it('should generate a doc object that matches the TokenTransferProxy fixture with its dependencies', async () => {
@@ -48,7 +52,7 @@ describe('#SolidityDocGenerator', () => {
         });
     });
     it('should generate a doc object that matches the TokenTransferProxy fixture', async () => {
-        const doc: DocAgnosticFormat = await generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, [
+        const doc: DocAgnosticFormat = await solDoc.generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, [
             'TokenTransferProxy',
         ]);
         verifyTokenTransferProxyABIIsDocumented(doc, 'TokenTransferProxy');
@@ -56,7 +60,7 @@ describe('#SolidityDocGenerator', () => {
     describe('when processing all the permutations of devdoc stuff that we use in our contracts', () => {
         let doc: DocAgnosticFormat;
         before(async () => {
-            doc = await generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, ['NatspecEverything']);
+            doc = await solDoc.generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, ['NatspecEverything']);
             expect(doc).to.not.be.undefined();
             expect(doc.NatspecEverything).to.not.be.undefined();
         });
@@ -159,7 +163,9 @@ describe('#SolidityDocGenerator', () => {
         });
     });
     it('should document a method that returns multiple values', async () => {
-        const doc = await generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, ['MultipleReturnValues']);
+        const doc = await solDoc.generateSolDocAsync(`${__dirname}/../../test/fixtures/contracts`, [
+            'MultipleReturnValues',
+        ]);
         expect(doc.MultipleReturnValues).to.not.be.undefined();
         expect(doc.MultipleReturnValues.methods).to.not.be.undefined();
         let methodWithMultipleReturnValues: SolidityMethod | undefined;