Use built-in getExecOutput

src/buildx.ts

@@ -1,28 +1,38 @@
 import * as semver from 'semver';
-import * as exec from './exec';
+import * as exec from '@actions/exec';
 
 export async function isAvailable(): Promise<Boolean> {
-  return await exec.exec(`docker`, ['buildx'], true).then(res => {
-    if (res.stderr != '' && !res.success) {
-      return false;
-    }
-    return res.success;
-  });
+  return await exec
+    .getExecOutput('docker', ['buildx'], {
+      ignoreReturnCode: true,
+      silent: true
+    })
+    .then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        return false;
+      }
+      return res.exitCode == 0;
+    });
 }
 
 export async function getVersion(): Promise<string> {
-  return await exec.exec(`docker`, ['buildx', 'version'], true).then(res => {
-    if (res.stderr != '' && !res.success) {
-      throw new Error(res.stderr);
-    }
-    return parseVersion(res.stdout);
-  });
+  return await exec
+    .getExecOutput('docker', ['buildx', 'version'], {
+      ignoreReturnCode: true,
+      silent: true
+    })
+    .then(res => {
+      if (res.stderr.length > 0 && res.exitCode != 0) {
+        throw new Error(res.stderr);
+      }
+      return parseVersion(res.stdout);
+    });
 }
 
 export async function parseVersion(stdout: string): Promise<string> {
   const matches = /\sv?([0-9.]+)/.exec(stdout);
   if (!matches) {
-    throw new Error(`Cannot parse Buildx version`);
+    throw new Error(`Cannot parse buildx version`);
   }
   return semver.clean(matches[1]);
 }