DOC-2457 - Adds code examples for the string tutorial

doctests/dt-string.js

@@ -0,0 +1,69 @@
+// EXAMPLE: string_tutorial
+// HIDE_START
+import assert from 'assert';
+import { createClient } from 'redis';
+
+const client = await createClient();
+await client.connect();
+// HIDE_END
+// REMOVE_START
+await client.flushDb();
+// REMOVE_END
+
+// STEP_START set
+const res1 = await client.set("bike:1", "Deimos");
+console.log(res1);  // true
+const res2 = await client.get("bike:1");
+console.log(res2);  // Deimos
+// STEP_END
+
+// REMOVE_START
+assert.equal(res1, 'OK');
+assert.equal(res2, 'Deimos');
+// REMOVE_END
+
+// STEP_START set_nx_xx
+// HIDE_START
+const res3 = await client.set("bike:1", "bike", 'NX');
+console.log(res3);  // None
+console.log(await client.get("bike:1"));  // Deimos
+const res4 = await client.set("bike:1", "bike", 'XX');
+console.log(res4);  // True
+// STEP_END
+
+// REMOVE_START
+assert.equal(res3, 'OK');
+assert.equal(res4, 'OK');
+// REMOVE_END
+
+// STEP_START mset
+const res5 = await client.mSet([
+  ["bike:1", "Deimos"],
+  ["bike:2", "Ares"],
+  ["bike:3", "Vanth"]
+]);
+
+console.log(res5);  // true
+const res6 = await client.mGet(["bike:1", "bike:2", "bike:3"]);
+console.log(res6);  // ['Deimos', 'Ares', 'Vanth']
+// STEP_END
+
+// REMOVE_START
+assert.equal(res5, 'OK');
+assert.deepEqual(res6, ["Deimos", "Ares", "Vanth"]);
+// REMOVE_END
+
+// STEP_START incr
+await client.set("total_crashes", 0);
+const res7 = await client.incr("total_crashes");
+console.log(res7); // 1
+const res8 = await client.incrBy("total_crashes", 10);
+console.log(res8); // 11
+// STEP_END
+
+// REMOVE_START
+assert.equal(res7, 1);
+assert.equal(res8, 11);
+// REMOVE_END
+
+await client.quit();