Add node querystring polyfill (#4370)

1 files changed, 70 insertions, 0 deletions

diff --git a/std/node/querystring.ts b/std/node/querystring.ts
new file mode 100644
index 000000000..a5b2e7f05
--- /dev/null
+++ b/std/node/querystring.ts
@@ -0,0 +1,70 @@
+interface ParseOptions {
+  decodeURIComponent?: (string: string) => string;
+  maxKeys?: number;
+}
+
+export function parse(
+  str: string,
+  sep = "&",
+  eq = "=",
+  { decodeURIComponent = unescape, maxKeys = 1000 }: ParseOptions = {}
+): { [key: string]: string[] | string } {
+  const entries = str
+    .split(sep)
+    .map(entry => entry.split(eq).map(decodeURIComponent));
+  const final: { [key: string]: string[] | string } = {};
+
+  let i = 0;
+  while (true) {
+    if ((Object.keys(final).length === maxKeys && !!maxKeys) || !entries[i]) {
+      break;
+    }
+
+    const [key, val] = entries[i];
+    if (final[key]) {
+      if (Array.isArray(final[key])) {
+        (final[key] as string[]).push(val);
+      } else {
+        final[key] = [final[key] as string, val];
+      }
+    } else {
+      final[key] = val;
+    }
+
+    i++;
+  }
+
+  return final;
+}
+
+interface StringifyOptions {
+  encodeURIComponent?: (string: string) => string;
+}
+
+export function stringify(
+  obj: object,
+  sep = "&",
+  eq = "=",
+  { encodeURIComponent = escape }: StringifyOptions = {}
+): string {
+  const final = [];
+
+  for (const entry of Object.entries(obj)) {
+    if (Array.isArray(entry[1])) {
+      for (const val of entry[1]) {
+        final.push(encodeURIComponent(entry[0]) + eq + encodeURIComponent(val));
+      }
+    } else if (typeof entry[1] !== "object" && entry[1] !== undefined) {
+      final.push(entry.map(encodeURIComponent).join(eq));
+    } else {
+      final.push(encodeURIComponent(entry[0]) + eq);
+    }
+  }
+
+  return final.join(sep);
+}
+
+export const decode = parse;
+export const encode = stringify;
+export const unescape = decodeURIComponent;
+export const escape = encodeURIComponent;