Add more tests to cover Page.pdf() method (#196) (#200)

This patch adds sanity tests to make sure Page.pdf() produces
sane results.

Fixes #166.

package.json

@@ -40,6 +40,7 @@
     "markdown-toc": "^1.1.0",
     "minimist": "^1.2.0",
     "ncp": "^2.0.0",
+    "pdfjs-dist": "^1.8.595",
     "pixelmatch": "^4.0.2",
     "pngjs": "^3.2.0",
     "text-diff": "^1.0.1"

test/test.js

@@ -1364,17 +1364,79 @@ describe('Page', function() {
     }));
   });
 
-  describe('Page.pdf', function() {
+  // Printing to pdf is currently only supported in headless
-    const outputFile = __dirname + '/assets/output.pdf';
+  (headless ? describe : xdescribe)('Page.pdf', function() {
-    afterEach(function() {
+    it('should be able to save file', SX(async function() {
-      fs.unlinkSync(outputFile);
+      const outputFile = __dirname + '/assets/output.pdf';
-    });
-
-    // Printing to pdf is currently only supported in headless
-    (headless ? it : xit)('should print to pdf', SX(async function() {
-      await page.navigate(PREFIX + '/grid.html');
       await page.pdf({path: outputFile});
       expect(fs.readFileSync(outputFile).byteLength).toBeGreaterThan(0);
+      fs.unlinkSync(outputFile);
+    }));
+    it('should default to printing in Letter format', SX(async function() {
+      let pages = await getPDFPages(await page.pdf());
+      expect(pages.length).toBe(1);
+      expect(pages[0].width).toBeCloseTo(8.5, 2);
+      expect(pages[0].height).toBeCloseTo(11, 2);
+    }));
+    it('should support setting custom format', SX(async function() {
+      let pages = await getPDFPages(await page.pdf({
+        format: 'A4'
+      }));
+      expect(pages.length).toBe(1);
+      expect(pages[0].width).toBeCloseTo(8.27, 1);
+      expect(pages[0].height).toBeCloseTo(11.7, 1);
+    }));
+    it('should support setting paper width and height', SX(async function() {
+      let pages = await getPDFPages(await page.pdf({
+        width: '10in',
+        height: '10in',
+      }));
+      expect(pages.length).toBe(1);
+      expect(pages[0].width).toBeCloseTo(10, 2);
+      expect(pages[0].height).toBeCloseTo(10, 2);
+    }));
+    it('should print multiple pages', SX(async function() {
+      await page.navigate(PREFIX + '/grid.html');
+      // Define width and height in CSS pixels.
+      const width = 50 * 5 + 1;
+      const height = 50 * 5 + 1;
+      let pages = await getPDFPages(await page.pdf({width, height}));
+      expect(pages.length).toBe(8);
+      expect(pages[0].width).toBeCloseTo(cssPixelsToInches(width), 2);
+      expect(pages[0].height).toBeCloseTo(cssPixelsToInches(height), 2);
+    }));
+    it('should support page ranges', SX(async function() {
+      await page.navigate(PREFIX + '/grid.html');
+      // Define width and height in CSS pixels.
+      const width = 50 * 5 + 1;
+      const height = 50 * 5 + 1;
+      let pages = await getPDFPages(await page.pdf({width, height, pageRanges: '1,4-7'}));
+      expect(pages.length).toBe(5);
+    }));
+    it('should throw if format is unknown', SX(async function() {
+      let error = null;
+      try {
+        await getPDFPages(await page.pdf({
+          format: 'something'
+        }));
+      } catch (e) {
+        error = e;
+      }
+      expect(error).toBeTruthy();
+      expect(error.message).toContain('Unknown paper format');
+    }));
+    it('should throw if units are unknown', SX(async function() {
+      let error = null;
+      try {
+        await getPDFPages(await page.pdf({
+          width: '10em',
+          height: '10em',
+        }));
+      } catch (e) {
+        error = e;
+      }
+      expect(error).toBeTruthy();
+      expect(error.message).toContain('Failed to parse parameter value');
     }));
   });
 
@@ -1529,6 +1591,39 @@ function waitForEvents(emitter, eventName, eventCount = 1) {
   }
 }
 
+/**
+ * @param {!Buffer} pdfBuffer
+ * @return {!Promise<!Array<!Object>>}
+ */
+async function getPDFPages(pdfBuffer) {
+  const PDFJS = require('pdfjs-dist');
+  PDFJS.disableWorker = true;
+  const data = new Uint8Array(pdfBuffer);
+  const doc = await PDFJS.getDocument(data);
+  let pages = [];
+  for (let i = 0; i < doc.numPages; ++i) {
+    let page = await doc.getPage(i + 1);
+    let viewport = page.getViewport(1);
+    // Viewport width and height is in PDF points, which is
+    // 1/72 of an inch.
+    pages.push({
+      width: viewport.width / 72,
+      height: viewport.height / 72,
+    });
+    page.cleanup();
+  }
+  doc.cleanup();
+  return pages;
+}
+
+/**
+ * @param {number} px
+ * @return {number}
+ */
+function cssPixelsToInches(px) {
+  return px / 96;
+}
+
 // Since Jasmine doesn't like async functions, they should be wrapped
 // in a SX function.
 function SX(fun) {

yarn.lock

@@ -27,6 +27,15 @@ ajv@^4.7.0:
     co "^4.6.0"
     json-stable-stringify "^1.0.1"
 
+ajv@^5.0.0:
+  version "5.2.2"
+  resolved "https://registry.yarnpkg.com/ajv/-/ajv-5.2.2.tgz#47c68d69e86f5d953103b0074a9430dc63da5e39"
+  dependencies:
+    co "^4.6.0"
+    fast-deep-equal "^1.0.0"
+    json-schema-traverse "^0.3.0"
+    json-stable-stringify "^1.0.1"
+
 ansi-escapes@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/ansi-escapes/-/ansi-escapes-2.0.0.tgz#5bae52be424878dd9783e8910e3fc2922e83c81b"
@@ -92,6 +101,10 @@ balanced-match@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/balanced-match/-/balanced-match-1.0.0.tgz#89b4d199ab2bee49de164ea02b89ce462d71b767"
 
+big.js@^3.1.3:
+  version "3.1.3"
+  resolved "https://registry.yarnpkg.com/big.js/-/big.js-3.1.3.tgz#4cada2193652eb3ca9ec8e55c9015669c9806978"
+
 bindings@~1.2.1:
   version "1.2.1"
   resolved "https://registry.yarnpkg.com/bindings/-/bindings-1.2.1.tgz#14ad6113812d2d37d72e67b4cacb4bb726505f11"
@@ -216,6 +229,10 @@ doctrine@^2.0.0:
     esutils "^2.0.2"
     isarray "^1.0.0"
 
+emojis-list@^2.0.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/emojis-list/-/emojis-list-2.1.0.tgz#4daa4d9db00f9819880c79fa457ae5b09a1fd389"
+
 "entities@~ 1.1.1":
   version "1.1.1"
   resolved "https://registry.yarnpkg.com/entities/-/entities-1.1.1.tgz#6e5c2d0a5621b5dadaecef80b90edfb5cd7772f0"
@@ -337,6 +354,10 @@ extract-zip@^1.6.5:
     mkdirp "0.5.0"
     yauzl "2.4.1"
 
+fast-deep-equal@^1.0.0:
+  version "1.0.0"
+  resolved "https://registry.yarnpkg.com/fast-deep-equal/-/fast-deep-equal-1.0.0.tgz#96256a3bc975595eb36d82e9929d060d893439ff"
+
 fast-levenshtein@~2.0.4:
   version "2.0.6"
   resolved "https://registry.yarnpkg.com/fast-levenshtein/-/fast-levenshtein-2.0.6.tgz#3d8a5c66883a16a30ca8643e851f19baa7797917"
@@ -585,12 +606,20 @@ jschardet@^1.4.2:
   version "1.4.2"
   resolved "https://registry.yarnpkg.com/jschardet/-/jschardet-1.4.2.tgz#2aa107f142af4121d145659d44f50830961e699a"
 
+json-schema-traverse@^0.3.0:
+  version "0.3.1"
+  resolved "https://registry.yarnpkg.com/json-schema-traverse/-/json-schema-traverse-0.3.1.tgz#349a6d44c53a51de89b40805c5d5e59b417d3340"
+
 json-stable-stringify@^1.0.1:
   version "1.0.1"
   resolved "https://registry.yarnpkg.com/json-stable-stringify/-/json-stable-stringify-1.0.1.tgz#9a759d39c5f2ff503fd5300646ed445f88c4f9af"
   dependencies:
     jsonify "~0.0.0"
 
+json5@^0.5.0:
+  version "0.5.1"
+  resolved "https://registry.yarnpkg.com/json5/-/json5-0.5.1.tgz#1eade7acc012034ad84e2396767ead9fa5495821"
+
 jsonify@~0.0.0:
   version "0.0.0"
   resolved "https://registry.yarnpkg.com/jsonify/-/jsonify-0.0.0.tgz#2c74b6ee41d93ca51b7b5aaee8f503631d252a73"
@@ -633,6 +662,14 @@ list-item@^1.1.1:
     is-number "^2.1.0"
     repeat-string "^1.5.2"
 
+loader-utils@^1.0.2:
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/loader-utils/-/loader-utils-1.1.0.tgz#c98aef488bcceda2ffb5e2de646d6a754429f5cd"
+  dependencies:
+    big.js "^3.1.3"
+    emojis-list "^2.0.0"
+    json5 "^0.5.0"
+
 lodash@^4.0.0, lodash@^4.17.4, lodash@^4.3.0:
   version "4.17.4"
   resolved "https://registry.yarnpkg.com/lodash/-/lodash-4.17.4.tgz#78203a4d1c328ae1d86dca6460e369b57f4055ae"
@@ -727,6 +764,10 @@ ncp@^2.0.0:
   version "2.0.0"
   resolved "https://registry.yarnpkg.com/ncp/-/ncp-2.0.0.tgz#195a21d6c46e361d2fb1281ba38b91e9df7bdbb3"
 
+node-ensure@^0.0.0:
+  version "0.0.0"
+  resolved "https://registry.yarnpkg.com/node-ensure/-/node-ensure-0.0.0.tgz#ecae764150de99861ec5c810fd5d096b183932a7"
+
 object-assign@^4.0.1:
   version "4.1.1"
   resolved "https://registry.yarnpkg.com/object-assign/-/object-assign-4.1.1.tgz#2109adc7965887cfc05cbbd442cac8bfbb360863"
@@ -772,6 +813,13 @@ path-is-inside@^1.0.1, path-is-inside@^1.0.2:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/path-is-inside/-/path-is-inside-1.0.2.tgz#365417dede44430d1c11af61027facf074bdfc53"
 
+pdfjs-dist@^1.8.595:
+  version "1.8.599"
+  resolved "https://registry.yarnpkg.com/pdfjs-dist/-/pdfjs-dist-1.8.599.tgz#20d55654f3b3b1a8394649a074d0baa1bd54060f"
+  dependencies:
+    node-ensure "^0.0.0"
+    worker-loader "^0.8.0"
+
 pend@~1.2.0:
   version "1.2.0"
   resolved "https://registry.yarnpkg.com/pend/-/pend-1.2.0.tgz#7a57eb550a6783f9115331fcf4663d5c8e007a50"
@@ -898,6 +946,12 @@ safe-buffer@~5.1.0:
   version "5.1.0"
   resolved "https://registry.yarnpkg.com/safe-buffer/-/safe-buffer-5.1.0.tgz#fe4c8460397f9eaaaa58e73be46273408a45e223"
 
+schema-utils@^0.3.0:
+  version "0.3.0"
+  resolved "https://registry.yarnpkg.com/schema-utils/-/schema-utils-0.3.0.tgz#f5877222ce3e931edae039f17eb3716e7137f8cf"
+  dependencies:
+    ajv "^5.0.0"
+
 set-getter@^0.1.0:
   version "0.1.0"
   resolved "https://registry.yarnpkg.com/set-getter/-/set-getter-0.1.0.tgz#d769c182c9d5a51f409145f2fba82e5e86e80376"
@@ -1024,6 +1078,13 @@ wordwrap@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/wordwrap/-/wordwrap-1.0.0.tgz#27584810891456a4171c8d0226441ade90cbcaeb"
 
+worker-loader@^0.8.0:
+  version "0.8.1"
+  resolved "https://registry.yarnpkg.com/worker-loader/-/worker-loader-0.8.1.tgz#e8e995331ea34df5bf68296824bfb7f0ad578d43"
+  dependencies:
+    loader-utils "^1.0.2"
+    schema-utils "^0.3.0"
+
 wrappy@1:
   version "1.0.2"
   resolved "https://registry.yarnpkg.com/wrappy/-/wrappy-1.0.2.tgz#b5243d8f3ec1aa35f1364605bc0d1036e30ab69f"