Resuse puppeteer browser instance (#5)

* move browser instance to closure

* update readme

README.md

@@ -22,25 +22,46 @@ All fonts that are used inside passed html document need to be installed on the
 Headers and footers could be generated by passing either as a separate html document or as a single line that can be customized to `left`, `center` and `right` sections.
 There are two special placeholders `{page}` and `{pages}` that could be used inside your document footers and headers, which are going to be replaced by current page number and total pages count respectively.
 `mkCompoundPdf` accepts array of html documents that would be concatenated. Total page count is going to be the sum of the final generated pdf.
-All documents had to be proper HTML documents. 
+All documents had to be proper HTML documents.
+
+For usage checkout `./src/compound-pdf.ts` file. For JS strip all types.
 
 ```ts
 import { PrintMargin, pageSizeInMM, mkCompoundPdf, mkPdf } from 'html-to-pdf-converter'
 const footerFontPath = join(
   __dirname, 'path_to_font/roboto-v18-latin_greek_cyrillic-regular.ttf',
 )
 
-// sizes are in millimeters
-const footerFontSize = 10
-const margin: PrintMargin = {
+const fontPath = join(__dirname, '../fonts/roboto-v18-latin_greek_cyrillic-regular.ttf')
+const footerFontSize = Millimeters.of(4.2)
+
+const margin: PrintMargin = PrintMargin.ofMillimeters({
   top: 7.5,
   right: 15,
   bottom: 5,
   left: 17,
+})
+
+const puppeteerOptions: MkPdfOptions = {
+  puppeteer: {
+    args: ['--no-sandbox', '--disable-setuid-sandbox', '--disable-dev-shm-usage'],
+  },
 }
 
-export const getPDFWithSimpleOneLineFooter= (document: string): Buffer => {
-  return mkCompoundPdf([
+// Initialize converter, puppeteer browser launch options could be passed in
+const converter: HtmlToPdfConverter = await initialize(puppeteerOptions)
+// When finished don't forget to release resources
+// await converter.destroy()
+
+// Converter signature
+export interface HtmlToPdfConverter {
+  mkCompoundPdf: (contents: PdfContentWithSlots[]) => Promise<Buffer>
+  mkPdf: (content: PdfContent) => Promise<Buffer>
+  destroy: () => Promise<void>
+}
+
+export const getPDFWithSimpleOneLineFooter= (document: string): Promise<Buffer> => {
+  converter.mkCompoundPdf([
     {
       pdfContent: document,
       footer: {
@@ -69,8 +90,8 @@ export const getPDFProtocolStream = (
   firstPage: string,
   firstPageFooter: string,
   restPages: string,
-): Buffer => {
-  return mkCompoundPdf([
+): Promise<Buffer> =>
+  converter.mkCompoundPdf([
     {
       pdfContent: firstPage,
       footer: {
@@ -102,10 +123,9 @@ export const getPDFProtocolStream = (
       pageSize: pageSizeInMM.A4.landscape,
     },
   ])
-}
 
-export const getPDFWithCustomSize = (document: string): Buffer =>
-  mkPdf({
+export const getPDFWithCustomSize = (document: string): Promise<Buffer> =>
+  converter.mkPdf({
     pdfContent: document,
     margin: {
       top: 5,

src/compound-pdf.spec.ts

@@ -1,9 +1,8 @@
 import { readFileSync } from 'fs'
 import { join } from 'path'
 
-import { mkCompoundPdf, MkPdfOptions } from '../src/compound-pdf'
 import { PrintMargin, pageSizeInMM } from '../src/types'
-import { Millimeters } from './index'
+import { initialize, MkPdfOptions, HtmlToPdfConverter, Millimeters } from './index'
 import { compareToExpectedMultiple, compareToExpected } from './utils/test-helpers'
 
 const headerHtml = readFileSync(join(__dirname, './test-files/header.html'), 'utf8')
@@ -21,47 +20,54 @@ const margin: PrintMargin = PrintMargin.ofMillimeters({
   left: 17,
 })
 
-// TODO: find out how to run without those options
-// Travis-CI Docker image workaround
-const puppeteerOptions: MkPdfOptions = {
-  puppeteer: {
-    args: ['--no-sandbox', '--disable-setuid-sandbox', '--disable-dev-shm-usage'],
-  },
-}
-
 const TEST_TIMEOUT = 10000 // 10 seconds
 const OUTPUT_NEW_EXPECTED_FILES = false
 
+let converter: HtmlToPdfConverter
+
+beforeAll(async () => {
+  // TODO: find out how to run without those options
+  // Travis-CI Docker image workaround
+  const puppeteerOptions: MkPdfOptions = {
+    puppeteer: {
+      args: ['--no-sandbox', '--disable-setuid-sandbox', '--disable-dev-shm-usage'],
+    },
+  }
+
+  converter = await initialize(puppeteerOptions)
+})
+
+afterAll(async () => {
+  await converter.destroy()
+})
+
 describe('mkCompoundPdf()', () => {
   it(
     'text footer',
     async () => {
-      const pdfBuffer = await mkCompoundPdf(
-        [
-          {
-            pdfContent: firstPageHtml,
-            footer: {
-              type: 'TextSlot',
-              left: {
-                fontPath: fontPath,
-                text: 'https://github.com/moshensky/html-to-pdf-converter',
-                size: footerFontSize,
-                underline: true,
-                color: 0x0060bf, // '#0060bf'
-              },
-              right: {
-                fontPath: fontPath,
-                text: 'Page {page} of {pages}',
-                size: footerFontSize,
-                color: 0x000000, // '#000000'
-              },
+      const pdfBuffer = await converter.mkCompoundPdf([
+        {
+          pdfContent: firstPageHtml,
+          footer: {
+            type: 'TextSlot',
+            left: {
+              fontPath: fontPath,
+              text: 'https://github.com/moshensky/html-to-pdf-converter',
+              size: footerFontSize,
+              underline: true,
+              color: 0x0060bf, // '#0060bf'
+            },
+            right: {
+              fontPath: fontPath,
+              text: 'Page {page} of {pages}',
+              size: footerFontSize,
+              color: 0x000000, // '#000000'
             },
-            margin,
-            pageSize: pageSizeInMM.A4.portrait,
           },
-        ],
-        puppeteerOptions,
-      )
+          margin,
+          pageSize: pageSizeInMM.A4.portrait,
+        },
+      ])
 
       await compareToExpected('textFooter', pdfBuffer, OUTPUT_NEW_EXPECTED_FILES)
     },
@@ -72,29 +78,26 @@ describe('mkCompoundPdf()', () => {
   it(
     'multiple pages with different html footers',
     async () => {
-      const pdfBuffer = await mkCompoundPdf(
-        [
-          {
-            pdfContent: firstPageHtml,
-            footer: {
-              type: 'HtmlSlot',
-              html: footerHtml,
-            },
-            margin,
-            pageSize: pageSizeInMM.A4.portrait,
+      const pdfBuffer = await converter.mkCompoundPdf([
+        {
+          pdfContent: firstPageHtml,
+          footer: {
+            type: 'HtmlSlot',
+            html: footerHtml,
           },
-          {
-            pdfContent: resultsHtml,
-            footer: {
-              type: 'HtmlSlot',
-              html: footerHtml,
-            },
-            margin,
-            pageSize: pageSizeInMM.A4.landscape,
+          margin,
+          pageSize: pageSizeInMM.A4.portrait,
+        },
+        {
+          pdfContent: resultsHtml,
+          footer: {
+            type: 'HtmlSlot',
+            html: footerHtml,
           },
-        ],
-        puppeteerOptions,
-      )
+          margin,
+          pageSize: pageSizeInMM.A4.landscape,
+        },
+      ])
 
       await compareToExpectedMultiple('htmlFooter', pdfBuffer, OUTPUT_NEW_EXPECTED_FILES)
     },
@@ -104,20 +107,17 @@ describe('mkCompoundPdf()', () => {
   it(
     'single page with html header',
     async () => {
-      const pdfBuffer = await mkCompoundPdf(
-        [
-          {
-            pdfContent: firstPageHtml,
-            header: {
-              type: 'HtmlSlot',
-              html: headerHtml,
-            },
-            margin,
-            pageSize: pageSizeInMM.A4.portrait,
+      const pdfBuffer = await converter.mkCompoundPdf([
+        {
+          pdfContent: firstPageHtml,
+          header: {
+            type: 'HtmlSlot',
+            html: headerHtml,
           },
-        ],
-        puppeteerOptions,
-      )
+          margin,
+          pageSize: pageSizeInMM.A4.portrait,
+        },
+      ])
 
       await compareToExpected('singlePageWithHtmlHeader', pdfBuffer, OUTPUT_NEW_EXPECTED_FILES)
     },

src/compound-pdf.ts

@@ -110,11 +110,10 @@ export interface MkPdfOptions {
   puppeteer?: puppeteer.LaunchOptions
 }
 
-export const mkCompoundPdf = async (
+const mkCompoundPdf = async (
   contents: PdfContentWithSlots[],
-  options: MkPdfOptions = {},
+  browser: puppeteer.Browser,
 ): Promise<Buffer> => {
-  const browser = await puppeteer.launch(options.puppeteer)
   const page = await browser.newPage()
   const pdfsWithSpaceForSlots: {
     content: PdfWithSpaceForSlots
@@ -147,20 +146,34 @@ export const mkCompoundPdf = async (
     startPage += pagesCount
   }
 
-  await browser.close()
+  await page.close()
 
   return appendPdfs(pdfsWithSlots)
 }
 
-export const mkPdf = async (
+const mkPdf = async (
   { margin, pageSize, pdfContent }: PdfContent,
-  options: MkPdfOptions = {},
+  browser: puppeteer.Browser,
 ): Promise<Buffer> => {
-  const browser = await puppeteer.launch(options.puppeteer)
   const page = await browser.newPage()
   const pdfBuffer = await mkSizedPdf(pdfContent, page, pageSize, margin)
-
-  await browser.close()
+  await page.close()
 
   return pdfBuffer
 }
+
+export interface HtmlToPdfConverter {
+  mkCompoundPdf: (contents: PdfContentWithSlots[]) => Promise<Buffer>
+  mkPdf: (content: PdfContent) => Promise<Buffer>
+  destroy: () => Promise<void>
+}
+
+export const initialize = async (options: MkPdfOptions = {}): Promise<HtmlToPdfConverter> => {
+  const browser = await puppeteer.launch(options.puppeteer)
+
+  return {
+    mkCompoundPdf: (contents: PdfContentWithSlots[]) => mkCompoundPdf(contents, browser),
+    mkPdf: (content: PdfContent) => mkPdf(content, browser),
+    destroy: () => browser.close(),
+  }
+}