Initial commit

Co-Authored-By: Eric Tuvesson <eric.tuvesson@gmail.com>
Co-Authored-By: mikaeltellhed <2311083+mikaeltellhed@users.noreply.github.com>
Co-Authored-By: kotte <14197736+mrtamagotchi@users.noreply.github.com>
Co-Authored-By: Anders Larsson <64838990+anders-topp@users.noreply.github.com>
Co-Authored-By: Johan  <4934465+joolsus@users.noreply.github.com>
Co-Authored-By: Tore Knudsen <18231882+torekndsn@users.noreply.github.com>
Co-Authored-By: victoratndl <99176179+victoratndl@users.noreply.github.com>

packages/noodl-git/src/core/show.ts

@@ -0,0 +1,48 @@
+import { ChildProcess } from 'child_process';
+import { git, GitExecutionOptions } from './client';
+
+/**
+ * Retrieve the contents of a file from the repository at a given
+ * reference, commit, or tree.
+ *
+ * Returns a promise that will produce a string Buffer instance containing
+ * the contents of the file or an error if the file doesn't
+ * exists in the given revision.
+ *
+ * @param repositoryDir - The repository directory from where to read the file
+ *
+ * @param commitish  - A commit SHA or some other identifier that
+ *                     ultimately dereferences to a commit/tree.
+ *
+ * @param path       - The file path, relative to the repository
+ *                     root from where to read the blob contents
+ */
+export async function getBlobContents(repositoryDir: string, commitish: string, path: string): Promise<string> {
+  const args = ['show', `${commitish}:${path}`];
+  const opts: GitExecutionOptions = {
+    parseErrors: false
+  };
+
+  const { output } = await git(args, repositoryDir, 'getBlobContents', opts);
+  return output;
+}
+
+export async function getBlobBinaryContents(repositoryDir: string, commitish: string, path: string): Promise<Buffer> {
+  const setBinaryEncoding: (process: ChildProcess) => void = (cb) => {
+    // If Node.js encounters a synchronous runtime error while spawning
+    // `stdout` will be undefined and the error will be emitted asynchronously
+    if (cb.stdout) {
+      cb.stdout.setEncoding('binary');
+    }
+  };
+
+  const args = ['show', `${commitish}:${path}`];
+  const opts: GitExecutionOptions = {
+    parseErrors: false,
+    processCallback: setBinaryEncoding
+  };
+
+  const { output } = await git(args, repositoryDir, 'getBlobBinaryContents', opts);
+
+  return Buffer.from(output, 'binary');
+}