function getDiagnostic()

in src/main.ts [639:673]
33 lines of code
9 McCabe index (conditional complexity)

function getDiagnostic(document: TextDocument, report: NpmListReport, moduleName: string, ranges: SourceRanges): Diagnostic | null {
	let diagnostic = null;

	// npm list only reports errors against 'dependencies' and not against 'devDependencies'
	if (report.dependencies && report.dependencies[moduleName]) {
		if (report.dependencies[moduleName]['missing'] === true) {
			if (ranges.dependencies[moduleName]) {
				const source = ranges.dependencies[moduleName].name;
				const range = new Range(document.positionAt(source.offset), document.positionAt(source.offset + source.length));
				diagnostic = new Diagnostic(range, `Module '${moduleName}' is not installed`, DiagnosticSeverity.Warning);
			} else {
				console.log(`[npm-script] Could not locate "missing" dependency '${moduleName}' in package.json`);
			}
		}
		else if (report.dependencies[moduleName]['invalid'] === true) {
			if (ranges.dependencies[moduleName]) {
				const source = ranges.dependencies[moduleName].version;
				const installedVersion = report.dependencies[moduleName]['version'];
				const range = new Range(document.positionAt(source.offset), document.positionAt(source.offset + source.length));
				const message = installedVersion ?
					`Module '${moduleName}' the installed version '${installedVersion}' is invalid` :
					`Module '${moduleName}' the installed version is invalid or has errors`;
				diagnostic = new Diagnostic(range, message, DiagnosticSeverity.Warning);
			} else {
				console.log(`[npm-script] Could not locate "invalid" dependency '${moduleName}' in package.json`);
			}
		}
		else if (report.dependencies[moduleName]['extraneous'] === true) {
			const source = findAttributeRange(ranges);
			const range = new Range(document.positionAt(source.offset), document.positionAt(source.offset + source.length));
			diagnostic = new Diagnostic(range, `Module '${moduleName}' is extraneous`, DiagnosticSeverity.Warning);
		}
	}
	return diagnostic;
}