function definitionLocation_godef()

in src/goDeclaration.ts [126:218]

• 85 lines of code
• 19 McCabe index (conditional complexity)

function definitionLocation_godef(
	input: GoDefinitionInput,
	token: vscode.CancellationToken,
	// eslint-disable-next-line @typescript-eslint/no-unused-vars
	useReceivers = true
): Promise<GoDefinitionInformation> {
	const godefTool = 'godef';
	const godefPath = getBinPath(godefTool);
	if (!path.isAbsolute(godefPath)) {
		return Promise.reject(missingToolMsg + godefTool);
	}
	const offset = byteOffsetAt(input.document, input.position);
	const env = toolExecutionEnvironment();
	env['GOROOT'] = getCurrentGoRoot();
	let p: cp.ChildProcess;
	if (token) {
		token.onCancellationRequested(() => killProcessTree(p));
	}

	return new Promise<GoDefinitionInformation>((resolve, reject) => {
		// Spawn `godef` process
		const args = ['-t', '-i', '-f', input.document.fileName, '-o', offset.toString()];
		// if (useReceivers) {
		// 	args.push('-r');
		// }
		p = cp.execFile(godefPath, args, { env, cwd: input.cwd }, (err, stdout, stderr) => {
			try {
				if (err && (<any>err).code === 'ENOENT') {
					return reject(missingToolMsg + godefTool);
				}
				if (err) {
					if (
						input.isMod &&
						!input.includeDocs &&
						stderr &&
						stderr.startsWith('godef: no declaration found for')
					) {
						promptToUpdateToolForModules(
							'godef',
							'To get the Go to Definition feature when using Go modules, please update your version of the "godef" tool.'
						);
						return reject(stderr);
					}
					if (stderr.indexOf('flag provided but not defined: -r') !== -1) {
						promptForUpdatingTool('godef');
						p = null;
						return definitionLocation_godef(input, token, false).then(resolve, reject);
					}
					return reject(err.message || stderr);
				}
				const result = stdout.toString();
				const lines = result.split('\n');
				let match = /(.*):(\d+):(\d+)/.exec(lines[0]);
				if (!match) {
					// TODO: Gotodef on pkg name:
					// /usr/local/go/src/html/template\n
					return resolve(null);
				}
				const [, file, line, col] = match;
				const pkgPath = path.dirname(file);
				const definitionInformation: GoDefinitionInformation = {
					file,
					line: +line - 1,
					column: +col - 1,
					declarationlines: lines.slice(1),
					toolUsed: 'godef',
					doc: null,
					name: null
				};
				if (!input.includeDocs || godefImportDefinitionRegex.test(definitionInformation.declarationlines[0])) {
					return resolve(definitionInformation);
				}
				match = /^\w+ \(\*?(\w+)\)/.exec(lines[1]);
				runGodoc(input.cwd, pkgPath, match ? match[1] : '', input.word, token)
					.then((doc) => {
						if (doc) {
							definitionInformation.doc = doc;
						}
						resolve(definitionInformation);
					})
					.catch((runGoDocErr) => {
						console.log(runGoDocErr);
						resolve(definitionInformation);
					});
			} catch (e) {
				reject(e);
			}
		});
		if (p.pid) {
			p.stdin.end(input.document.getText());
		}
	});
}