Merge pull request #101 from snyk/fix/go-binary-explicit-error

fix: go binary explicit error

lib/index.ts

@@ -1,6 +1,7 @@
 import * as fs from 'fs';
 import * as path from 'path';
 import * as tmp from 'tmp';
+import { lookpath } from 'lookpath';
 import debugLib = require('debug');
 import * as graphlib from '@snyk/graphlib';
 import { DepGraphBuilder, DepGraph } from '@snyk/dep-graph';
@@ -43,6 +44,11 @@ interface Options {
 export async function inspect(root, targetFile, options: Options = {}) {
   options.debug ? debugLib.enable('snyk-go-plugin') : debugLib.disable();
 
+  const goPath = await lookpath('go');
+  if (!goPath) {
+    throw new Error('The "go" command is not available on your system. To scan your dependencies in the CLI, you must ensure you have first installed the relevant package manager.');
+  }
+
   const result = await Promise.all([
     getMetaData(root, targetFile),
     getDependencies(root, targetFile, options.args),

package.json

@@ -27,6 +27,7 @@
     "@snyk/dep-graph": "^1.23.1",
     "@snyk/graphlib": "2.1.9-patch.3",
     "debug": "^4.1.1",
+    "lookpath": "^1.2.2",
     "snyk-go-parser": "1.4.1",
     "tmp": "0.2.1",
     "tslib": "^1.10.0"