Improve Graphviz support detection

customcommander · customcommander · commit 73c6126d98e4 · 2021-03-12T16:21:33.000Z
Previous implementation was assuming that an error was always caused by the Graphviz binary not available in the path. However an error can also be thrown when Graphviz is missing an external dependencies for example. As far as I know ENOENT stands for a no entry error which indicates that something wasn't found. In this case it should be safe to assume that Graphviz isn't available in the path. See: https://stackoverflow.com/q/66602685/1244884
diff --git a/lib/graph.js b/lib/graph.js
@@ -28,7 +28,11 @@ async function checkGraphvizInstalled(config) {
 	try {
 		await exec(cmd, ['-V']);
 	} catch (err) {
-		throw new Error(`Graphviz could not be found. Ensure that "gvpr" is in your $PATH. ${err}`);
+		if (err.code === 'ENOENT') {
+			throw new Error(`Graphviz could not be found. Ensure that "gvpr" is in your $PATH. ${err}`);
+		} else {
+			throw new Error(`Unexpected error when calling Graphviz "${cmd}". ${err}`);
+		}
 	}
 }
 

Original file line number	Diff line number	Diff line change
`@@ -28,7 +28,11 @@ async function checkGraphvizInstalled(config) {`
`28`	`28`	`try {`
`29`	`29`	`await exec(cmd, ['-V']);`
`30`	`30`	`} catch (err) {`
`31`		- throw new Error(`Graphviz could not be found. Ensure that "gvpr" is in your $PATH. ${err}`);
	`31`	`+ if (err.code === 'ENOENT') {`
	`32`	+ throw new Error(`Graphviz could not be found. Ensure that "gvpr" is in your $PATH. ${err}`);
	`33`	`+ } else {`
	`34`	+ throw new Error(`Unexpected error when calling Graphviz "${cmd}". ${err}`);
	`35`	`+ }`
`32`	`36`	`}`
`33`	`37`	`}`
`34`	`38`