From 369a63f03f263d81f576fb9f38afd80cf3b95f96 Mon Sep 17 00:00:00 2001
From: Dan Hensby <git@hens.by>
Date: Mon, 7 Aug 2023 21:56:45 +0200
Subject: [PATCH] feat: add connection string builder

---
 src/builder/index.ts              | 49 +++++++++++++++++++++++++++++++
 src/index.ts                      |  2 ++
 test/builder/connection-string.ts | 21 +++++++++++++
 3 files changed, 72 insertions(+)
 create mode 100644 src/builder/index.ts
 create mode 100644 test/builder/connection-string.ts

diff --git a/src/builder/index.ts b/src/builder/index.ts
new file mode 100644
index 0000000..1bb9c23
--- /dev/null
+++ b/src/builder/index.ts
@@ -0,0 +1,49 @@
+type ValidDataTypes = string | boolean | number | null | undefined | { toString(): string };
+
+function isQuoted(val: string): boolean {
+    if (val[0] !== '{') {
+        return false;
+    }
+    for (let i = 1; i < val.length; i++) {
+        if (val[i] === '}') {
+            if (i + 1 === val.length) {
+                // if last char, then it's quoted properly
+                return true;
+            } else if (val[i + 1] !== '}') {
+                // the next char is no a `}` so there is no valid escaping here
+                return false;
+            } else {
+                // we are seeing an escaped `}`, so skip ahead
+                i++;
+            }
+        }
+    }
+    return false;
+}
+
+function needsQuotes(val: string): boolean {
+    return !isQuoted(val) && !!val.match(/\[|]|{|}|\|\(|\)|,|;|\?|\*|=|!|@/)?.length;
+}
+
+function encodeTuple(key: string, value: ValidDataTypes): [string, string] {
+    if (value === null || value === undefined) {
+        return [key, ''];
+    }
+    switch (typeof value) {
+        case 'boolean':
+            return [key, value ? 'Yes' : 'No'];
+        default: {
+            const strVal = (value as { toString(): string }).toString();
+            if (needsQuotes(strVal)) {
+                return [key, `{${strVal.replace(/}/g, '}}')}}`];
+            }
+            return [key, strVal];
+        }
+    }
+}
+
+export function buildConnectionString(data: Record<string, ValidDataTypes>): string {
+    return Object.entries(data).map(([key, value]) => {
+        return encodeTuple(key.trim(), value).join('=');
+    }).join(';');
+}
diff --git a/src/index.ts b/src/index.ts
index cf40537..7365372 100644
--- a/src/index.ts
+++ b/src/index.ts
@@ -1,6 +1,8 @@
 import parseConnectionString from './parser/connection-string';
 import parseSqlConnectionString from './parser/sql-connection-string';
 
+export * from './builder';
+
 export {
     parseConnectionString,
     parseSqlConnectionString,
diff --git a/test/builder/connection-string.ts b/test/builder/connection-string.ts
new file mode 100644
index 0000000..dd012be
--- /dev/null
+++ b/test/builder/connection-string.ts
@@ -0,0 +1,21 @@
+import { buildConnectionString } from '../../src/builder';
+import { expect } from 'chai';
+
+describe('builder', () => {
+    it('builds a connection string', () => {
+        const built = buildConnectionString({
+            strkey: 'value',
+            booltrue: true,
+            boolfalse: false,
+            numkey: 123,
+            needsquote: 'a}test',
+            quotedquote: '{quoted}}value}',
+            quoted: '{regular value}',
+            badlyquoted: '{no closing quote',
+            badclose: '{close}early',
+            nullkey: null,
+            undefinedkey: undefined,
+        });
+        expect(built).to.equal('strkey=value;booltrue=Yes;boolfalse=No;numkey=123;needsquote={a}}test};quotedquote={quoted}}value};quoted={regular value};badlyquoted={{no closing quote};badclose={{close}}early};nullkey=;undefinedkey=');
+    });
+});