chore: make vault action consumable (#43)

* chore: make vault action consumable

* fix prefixless queries to default to data

* fix the right build entrypoint

* make output more forgiving and shore up selectors

* clarify doc language

* add npmtoken

src/secrets.js

@@ -0,0 +1,76 @@
+const jsonata = require("jsonata");
+
+
+/**
+ * @typedef {Object} SecretRequest
+ * @property {string} path
+ * @property {string} selector
+ */
+
+/**
+ * @template {SecretRequest} TRequest
+ * @typedef {Object} SecretResponse
+ * @property {TRequest} request
+ * @property {string} value
+ * @property {boolean} cachedResponse
+ */
+
+ /**
+  * @template TRequest
+  * @param {Array<TRequest>} secretRequests
+  * @param {import('got').Got} client
+  * @return {Promise<SecretResponse<TRequest>[]>}
+  */
+async function getSecrets(secretRequests, client) {
+    const responseCache = new Map();
+    const results = [];
+    for (const secretRequest of secretRequests) {
+        const { path, selector } = secretRequest;
+
+        const requestPath = `v1${path}`;
+        let body;
+        let cachedResponse = false;
+        if (responseCache.has(requestPath)) {
+            body = responseCache.get(requestPath);
+            cachedResponse = true;
+        } else {
+            const result = await client.get(requestPath);
+            body = result.body;
+            responseCache.set(requestPath, body);
+        }
+
+        const value = selectData(JSON.parse(body), selector);
+        results.push({
+            request: secretRequest,
+            value,
+            cachedResponse
+        });
+    }
+    return results;
+}
+
+/**
+ * Uses a Jsonata selector retrieve a bit of data from the result
+ * @param {object} data 
+ * @param {string} selector 
+ */
+function selectData(data, selector) {
+    const ata = jsonata(selector);
+    let result = JSON.stringify(ata.evaluate(data));
+    // Compat for custom engines
+    if (!result && ata.ast().type === "path" && ata.ast()['steps'].length === 1 && selector !== 'data' && 'data' in data) {
+        result = JSON.stringify(jsonata(`data.${selector}`).evaluate(data));
+    } else if (!result) {
+        throw Error(`Unable to retrieve result for ${selector}. No match data was found. Double check your Key or Selector.`);
+    }
+
+    if (result.startsWith(`"`)) {
+        result = result.substring(1, result.length - 1);
+    }
+    return result;
+}
+
+module.exports = {
+    getSecrets,
+    selectData
+}