feat: pull request backporting

feat: backport still open pull requests

src/service/args/args-parser.ts

@@ -0,0 +1,10 @@
+import { Args } from "@bp/service/args/args.types";
+
+/**
+ * Abstract arguments parser interface in charge to parse inputs and 
+ * produce a common Args object
+ */
+export default interface ArgsParser {
+
+  parse(): Args;
+}

src/service/args/args.types.ts

@@ -0,0 +1,11 @@
+/**
+ * Input arguments
+ */
+export interface Args {
+  dryRun: boolean, // if enabled do not push anything remotely
+  auth: string, // git service auth, like github token
+  targetBranch: string,  // branch on the target repo where the change should be backported to
+  pullRequest: string, // url of the pull request to backport
+  folder?: string, // local folder where the repositories should be cloned
+  author?: string, // backport pr author, default taken from pr
+}

src/service/args/cli/cli-args-parser.ts

@@ -0,0 +1,34 @@
+import ArgsParser from "@bp/service/args/args-parser";
+import { Args } from "@bp/service/args/args.types";
+import { Command } from "commander";
+import { name, version, description } from "@bp/../package.json";
+
+
+export default class CLIArgsParser implements ArgsParser {
+
+  private getCommand(): Command {
+    return new Command(name)
+      .version(version)
+      .description(description)
+      .requiredOption("-tb, --target-branch <branch>", "branch where changes must be backported to.")
+      .requiredOption("-pr, --pull-request <pr url>", "pull request url, e.g., https://github.com/lampajr/backporting/pull/1.")
+      .option("-d, --dry-run", "if enabled the tool does not create any pull request nor push anything remotely", false)
+      .option("-a, --auth <auth>", "git service authentication string, e.g., github token.", "")
+      .option("-f, --folder <folder>", "local folder where the repo will be checked out, e.g., /tmp/folder.", undefined);
+  }
+
+  parse(): Args {
+    const opts = this.getCommand()
+      .parse()
+      .opts();
+    
+    return {
+      dryRun: opts.dryRun,
+      auth: opts.auth,
+      pullRequest: opts.pullRequest,
+      targetBranch: opts.targetBranch,
+      folder: opts.folder
+    };
+  }
+
+}

src/service/args/gha/gha-args-parser.ts

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+import ArgsParser from "@bp/service/args/args-parser";
+import { Args } from "@bp/service/args/args.types";
+import { getInput } from "@actions/core";
+
+export default class GHAArgsParser implements ArgsParser {
+
+  parse(): Args {
+    return {
+      dryRun: getInput("dry-run") === "true",
+      auth: getInput("auth") ? getInput("auth") : "",
+      pullRequest: getInput("pull-request"),
+      targetBranch: getInput("target-branch"),
+      folder: getInput("folder") !== "" ? getInput("folder") : undefined
+    };
+  }
+
+}