Fixes #748, tests for prql-js (#833)

* For #748 , tests for javascript package

.github/workflows/release.yaml

@@ -78,6 +78,10 @@ jobs:
           node-version: "18.x"
           registry-url: "https://registry.npmjs.org"
 
+      - name: Run prql tests for node
+        run: npm i && npm run test
+        working-directory: prql-js/tests/
+
       - name: Publish package on npm
         run: npm publish
         working-directory: prql-js/

prql-js/tests/package.json

@@ -0,0 +1,20 @@
+{
+  "description": "Javascript tests for prql-js",
+  "files": [
+    "package.json"
+  ],
+  "license": "Apache-2.0",
+  "name": "prql-js",
+  "repository": {
+    "type": "git",
+    "url": "https://github.com/prql/prql"
+  },
+  "scripts": {
+    "test": "mocha ."
+  },
+  "version": "0.2.2",
+  "dependencies": {
+    "chai": "^4.3.6",
+    "mocha": "^10.0.0"
+  }
+}

prql-js/tests/test_all.js

@@ -0,0 +1,66 @@
+const assert = require("assert");
+const expect = require("chai").expect;
+const prql = require("../dist/node");
+const print = console.log;
+const employee_prql = `from employees
+join salaries [emp_no]
+group [emp_no, gender] (
+  aggregate [
+    emp_salary = average salary
+  ]
+)
+join de=dept_emp [emp_no]
+join dm=dept_manager [
+  (dm.dept_no == de.dept_no) and s"(de.from_date, de.to_date) OVERLAPS (dm.from_date, dm.to_date)"
+]
+group [dm.emp_no, gender] (
+  aggregate [
+    salary_avg = average emp_salary,
+    salary_sd = stddev emp_salary
+  ]
+)
+derive mng_no = dm.emp_no
+join managers=employees [emp_no]
+derive mng_name = s"managers.first_name || ' ' || managers.last_name"
+select [mng_name, managers.gender, salary_avg, salary_sd]`;
+
+describe("prql-js", () => {
+  describe("to_sql", () => {
+    it("should return valid sql from valid prql", () => {
+      const sql = prql.to_sql(employee_prql);
+      assert(
+        sql.trim().toLowerCase().startsWith("with") ||
+          sql.trim().toLowerCase().startsWith("select")
+      );
+    });
+
+    it("should throw an error on invalid prql", () => {
+      expect(() =>
+        prql.to_sql("Mississippi has four S’s and four I’s.")
+      ).to.throw("Error");
+    });
+  });
+
+  describe("compile", () => {
+    it("should return valid compile result for compile", () => {
+      const res = prql.compile(employee_prql);
+      expect(res.error).to.be.undefined;
+    });
+
+    it("should return  compile result with errors for compile", () => {
+      const res = prql.compile("Can you spell that without using S or I?");
+      expect(res.error).to.not.be.null;
+    });
+  });
+
+  describe("to_json", () => {
+    it("should return valid json  from valid prql", () => {
+      const js = JSON.parse(prql.to_json(employee_prql));
+      assert.equal(js.nodes.length, 1);
+    });
+
+    it("should throw an error on invalid prql", () => {
+      expect(() => prql.to_json("Answer: T-H-A-T!"));
+    });
+  });
+});