Added the ability to replace some placeholders in the screeps code (#12)

added the `git-replace` option.
Replaceing {{gitRef}}, {{deployTime}} and {{gitHash}}.

Reviewed-on: #12
Co-authored-by: Philipp Horstenkamp <philipp@horstenkamp.de>
Co-committed-by: Philipp Horstenkamp <philipp@horstenkamp.de>

index.js

@@ -4,6 +4,69 @@ const fs = require("fs");
 const glob = require("glob");
 const path = require("path");
 
+/**
+ * Replaces specific placeholder strings within the provided content with corresponding dynamic values.
+ *
+ * This function specifically targets three placeholders:
+ * - {{gitHash}} is replaced with the current Git commit hash, obtained from the GITHUB_SHA environment variable.
+ * - {{gitRef}} is replaced with the Git reference (branch or tag) that triggered the workflow, obtained from the GITHUB_REF environment variable.
+ * - {{deployTime}} is replaced with the current ISO timestamp.
+ *
+ * Note: This function is designed for use within a GitHub Actions workflow where GITHUB_SHA and GITHUB_REF environment variables are automatically set.
+ *
+ * @param {string} content - The string content in which placeholders are to be replaced.
+ * @returns {string} The content with placeholders replaced by their respective dynamic values.
+ */
+function replacePlaceholders(content) {
+  const deployTime = new Date().toISOString();
+  return content
+    .replace(/{{gitHash}}/g, process.env.GITHUB_SHA)
+    .replace(/{{gitRef}}/g, process.env.GITHUB_REF)
+    .replace(/{{deployTime}}/g, deployTime);
+}
+
+/**
+ * Reads all files matching a specified pattern, replaces certain placeholders in their content, and writes the updated content back to the files.
+ *
+ * This function searches for files in the filesystem using the provided glob pattern, optionally prefixed. It reads each file,
+ * uses the `replacePlaceholders` function to replace specific placeholders in the file's content, and then writes the modified content
+ * back to the original file. This is useful for dynamically updating file contents in a batch process, such as during a build or deployment.
+ *
+ * @param {string} pattern - The glob pattern used to find files. Example: '*.js' for all JavaScript files.
+ * @param {string} [prefix] - An optional directory prefix to prepend to the glob pattern. This allows searching within a specific directory.
+ * @returns {Promise<string[]>} A promise that resolves with an array of file paths that were processed, or rejects with an error if the process fails.
+ */
+async function readReplaceAndWriteFiles(pattern, prefix) {
+  return new Promise((resolve, reject) => {
+    const globPattern = prefix ? path.join(prefix, pattern) : pattern;
+
+    glob(globPattern, async (err, files) => {
+      if (err) {
+        return reject(err);
+      }
+      let processPromises = [];
+
+      files.forEach((file) => {
+        let processPromise = fs.promises
+          .readFile(file, "utf8")
+          .then((content) => {
+            content = replacePlaceholders(content);
+            return fs.promises.writeFile(file, content);
+          });
+
+        processPromises.push(processPromise);
+      });
+
+      try {
+        await Promise.all(processPromises);
+        resolve(files);
+      } catch (processError) {
+        reject(processError);
+      }
+    });
+  });
+}
+
 /**
  * Reads files matching a glob pattern into a dictionary.
  * @param {string} pattern - Glob pattern to match files.
@@ -88,6 +151,12 @@ async function postCode() {
   const pattern = core.getInput("pattern") || "*.js";
   const branch = core.getInput("branch") || "default";
 
+  const gitReplace = core.getInput("git-replace") || null;
+
+  if (gitReplace) {
+    await readReplaceAndWriteFiles(gitReplace, prefix);
+  }
+
   const files_to_push = await readFilesIntoDict(pattern, prefix);
 
   core.info(`Trying to upload the following files to ${branch}:`);
@@ -134,5 +203,4 @@ async function postCode() {
       });
   }
 }
-
 postCode();