initial changes

src/distibutions/official_builds/rc/rc_builds.ts

@@ -0,0 +1,50 @@
+import * as core from '@actions/core';
+
+import * as semver from 'semver';
+
+import BaseDistribution from '../../base-distribution';
+import {INodejs, INodeVersion} from '../../base-models';
+
+export default class RcBuild extends BaseDistribution {
+  constructor(nodeInfo: INodejs) {
+    super(nodeInfo);
+  }
+
+  protected async getNodejsVersions(): Promise<INodeVersion[]> {
+    const initialUrl = this.getDistributionUrl();
+    const dataUrl = `${initialUrl}/index.json`;
+
+    let response = await this.httpClient.getJson<INodeVersion[]>(dataUrl);
+    return response.result || [];
+  }
+
+  protected evaluateVersions(nodeVersions: INodeVersion[]): string {
+    let version = '';
+    const versions = this.filterVersions(nodeVersions);
+    core.debug(`evaluating ${versions.length} versions`);
+
+    for (let i = versions.length - 1; i >= 0; i--) {
+      const potential: string = versions[i];
+      const satisfied: boolean = semver.satisfies(
+        potential,
+        this.nodeInfo.versionSpec
+      );
+      if (satisfied) {
+        version = potential;
+        break;
+      }
+    }
+
+    if (version) {
+      core.debug(`matched: ${version}`);
+    } else {
+      core.debug('match not found');
+    }
+
+    return version;
+  }
+
+  getDistributionUrl(): string {
+    return 'https://nodejs.org/download/rc';
+  }
+}