Add output unit test to pagedown

.gitignore

@@ -2,3 +2,5 @@
 .Rhistory
 .RData
 .Ruserdata
+node_modules
+tests/test-output/*.html

jest.config.js

@@ -0,0 +1,9 @@
+const config = {
+    verbose: false,
+    // transform: {
+    //     "^.+\\.html?$": "html-loader-jest"
+    // },
+    preset: "jest-puppeteer"
+};
+
+module.exports = config;

package.json

@@ -0,0 +1,8 @@
+{
+  "devDependencies": {
+    "jest": "^27.3.1",
+    "jest-puppeteer": "^6.0.0",
+    "puppeteer": "^11.0.0",
+    "puppeteer-core": "^11.0.0"
+  }
+}

tests/test-output/longtable.Rmd

@@ -0,0 +1,14 @@
+---
+output:
+  pagedown::html_paged
+---
+
+```{r, echo=FALSE, message=FALSE, results=FALSE}
+data(iris)
+```
+
+# Table Test
+
+```{r, echo=FALSE}
+knitr::kable(iris)
+```

tests/test-output/longtable.test.js

@@ -0,0 +1,44 @@
+const exec = require('child_process').execSync;
+
+describe("Long tables", () => {
+    // TODO encapsulate the file path to make it easier to replicate in other tests
+    const cwd = process.cwd();
+    const file = 'longtable'
+    const rmdFile = cwd + '/tests/test-output/' + file + '.Rmd';
+    const htmlFile = cwd + '/tests/test-output/' + file + '.html';
+    const htmlFileUri = 'file://' + cwd + '/tests/test-output/' + file + '.html';
+
+    beforeAll(async () => {
+        exec('Rscript -e "rmarkdown::render(\'' + rmdFile + '\')"');
+        await page.goto(htmlFileUri, { waitUntil: "networkidle2" });
+    });
+
+    afterAll(() => {
+        exec('rm \'' + htmlFile + '\'');
+    });
+
+
+    it("Must page break", async () => {
+         const pageCount = await page.$$eval(
+            'div.pagedjs_page', 
+            (el) => el.length);
+
+        expect(pageCount).toEqual(8);
+    });
+
+    it("Must break table", async () => {
+        const tableCount = await page.$$eval(
+           'table', 
+           (el) => el.length);
+
+       expect(tableCount).toEqual(6);
+   });
+
+    it("Must page repeat thead", async () => {
+        const theadCount = await page.$$eval(
+           'thead', 
+           (el) => el.length);
+
+       expect(theadCount).toEqual(6);
+   });
+});