feat(query): bruno-query package

packages/bruno-query/src/index.ts

@@ -0,0 +1,134 @@
+/**
+ * If value is an array returns the deeply flattened array, otherwise value
+ */
+function normalize(value: any) {
+  if (!Array.isArray(value)) return value;
+
+  const values = [] as any[];
+
+  value.forEach(item => {
+    const value = normalize(item);
+    if (value != null) {
+      values.push(...Array.isArray(value) ? value : [value]);
+    }
+  });
+
+  return values.length ? values : undefined;
+}
+
+/**
+ * Gets value of a prop from source.
+ * 
+ * If source is an array get value for each item.
+ * 
+ * If deep is true then recursively gets values for prop in nested objects.
+ * 
+ * Once a value if found will not recurese further into that value.
+ */
+function getValue(source: any, prop: string, deep = false): any {
+  if (typeof source !== 'object') return;
+
+  let value;
+
+  if (Array.isArray(source)) {
+    value = source.map(item => getValue(item, prop, deep));
+  } else {
+    value = source[prop];
+    if (deep) {
+      value = [value];
+      for (const [key, item] of Object.entries(source)) {
+        if (key !== prop && typeof item === 'object') {
+          value.push(getValue(source[key], prop, deep));
+        }
+      }
+    }
+  }
+
+  return normalize(value);
+}
+
+type PredicateOrMapper = (obj: any) => any;
+
+/**
+ * Apply filter on source array or object
+ * 
+ * If the filter returns a non boolean non null value it is treated as a mapped value
+ */
+function filterOrMap(source: any, fun: PredicateOrMapper) {
+  const isArray = Array.isArray(source);
+  const list = isArray ? source : [source];
+  const result = [] as any[];
+  for (const item of list) {
+    if (item == null) continue;
+    const value = fun(item);
+    if (value === true) {
+      result.push(item);  // predicate
+    } else if (value != null && value !== false) {
+      result.push(value); // mapper
+    }
+  }
+  return isArray ? result : result[0];
+}
+
+/**
+ * Getter with deep navigation, filter and map support
+ * 
+ * 1. Easy array navigation
+ *    ```js
+ *    get(data, 'customer.orders.items.amount')
+ *    ```
+ * 2. Deep navigation .. double dots
+ *    ```js
+ *    get(data, '..items.amount')
+ *    ```
+ * 3. Array indexing
+ *    ```js
+ *    get(data, '..items[0].amount')
+ *    ```
+ * 4. Array filtering [?] with corresponding filter function
+ *    ```js
+ *    get(data, '..items[?].amount', i => i.amount > 20) 
+ *    ```
+ * 5. Array mapping [?] with corresponding mapper function
+ *    ```js
+ *    get(data, '..items[?].amount', i => i.amount + 10) 
+ *    ```
+ */
+export function get(source: any, path: string, ...fns: PredicateOrMapper[]) {
+  const paths = path
+    .replace(/\s+/g, '')
+    .split(/(\.{1,2}|\[\?\]|\[\d+\])/g) // ["..", "items", "[?]", ".", "amount", "[0]" ]
+    .filter(s => s.length > 0)
+    .map(str => {
+      str = str.replace(/\[|\]/g, '');
+      const index = parseInt(str);
+      return isNaN(index) ? str : index;
+    });
+
+  let index = 0, lookbehind = '' as string | number, funIndex = 0;
+
+  while (source != null && index < paths.length) {
+    const token = paths[index++];
+
+    switch (true) {
+      case token === "..":
+      case token === ".":
+        break;
+      case token === "?":
+        const fun = fns[funIndex++];
+        if (fun == null)
+          throw new Error(`missing function for ${lookbehind}`);
+        source = filterOrMap(source, fun);
+        break;
+      case typeof token === 'number':
+        source = source[token];
+        break;
+      default:
+        source = getValue(source, token as string, lookbehind === "..");
+    }
+
+    lookbehind = token;
+  }
+
+  return source;
+}