How to use ReadFile method of got Package

1// Copyright 2012 The Go Authors. All rights reserved.2// Use of this source code is governed by a BSD-style3// license that can be found in the LICENSE file.4package present5import (6	"fmt"7	"html/template"8	"strings"9	"testing"10)11func TestParseCode(t *testing.T) {12	// Enable play but revert the change at the end.13	defer func(play bool) { PlayEnabled = play }(PlayEnabled)14	PlayEnabled = true15	helloTest := []byte(`16package main17import "fmt"18func main() {19	fmt.Println("hello, test")20}21`)22	helloTestHTML := template.HTML(`23<pre><span num="2">package main</span>24<span num="3"></span>25<span num="4">import &#34;fmt&#34;</span>26<span num="5"></span>27<span num="6">func main() {</span>28<span num="7">    fmt.Println(&#34;hello, test&#34;)</span>29<span num="8">}</span>30</pre>31`)32	helloTestHL := []byte(`33package main34import "fmt" // HLimport35func main() { // HLfunc36	fmt.Println("hello, test") // HL37}38`)39	highlight := func(h template.HTML, s string) template.HTML {40		return template.HTML(strings.Replace(string(h), s, "<b>"+s+"</b>", -1))41	}42	read := func(b []byte, err error) func(string) ([]byte, error) {43		return func(string) ([]byte, error) { return b, err }44	}45	tests := []struct {46		name       string47		readFile   func(string) ([]byte, error)48		sourceFile string49		cmd        string50		err        string51		Code52	}{53		{54			name:       "all code, no play",55			readFile:   read(helloTest, nil),56			sourceFile: "main.go",57			cmd:        ".code main.go",58			Code: Code{59				Ext:      ".go",60				FileName: "main.go",61				Raw:      helloTest,62				Text:     helloTestHTML,63			},64		},65		{66			name:       "all code, play",67			readFile:   read(helloTest, nil),68			sourceFile: "main.go",69			cmd:        ".play main.go",70			Code: Code{71				Ext:      ".go",72				FileName: "main.go",73				Play:     true,74				Raw:      helloTest,75				Text:     helloTestHTML,76			},77		},78		{79			name:       "all code, highlighted",80			readFile:   read(helloTestHL, nil),81			sourceFile: "main.go",82			cmd:        ".code main.go",83			Code: Code{84				Ext:      ".go",85				FileName: "main.go",86				Raw:      helloTestHL,87				Text:     highlight(helloTestHTML, "fmt.Println(&#34;hello, test&#34;)"),88			},89		},90		{91			name:       "highlight only func",92			readFile:   read(helloTestHL, nil),93			sourceFile: "main.go",94			cmd:        ".code main.go HLfunc",95			Code: Code{96				Ext:      ".go",97				FileName: "main.go",98				Play:     false,99				Raw:      []byte("package main\n\nimport \"fmt\" // HLimport\n\nfunc main() { // HLfunc\n\tfmt.Println(\"hello, test\") // HL\n}"),100				Text:     highlight(helloTestHTML, "func main() {"),101			},102		},103		{104			name:       "bad highlight syntax",105			readFile:   read(helloTest, nil),106			sourceFile: "main.go",107			cmd:        ".code main.go HL",108			err:        "invalid highlight syntax",109		},110		{111			name:       "error reading file",112			readFile:   read(nil, fmt.Errorf("nope")),113			sourceFile: "main.go",114			cmd:        ".code main.go",115			err:        "main.go:0: nope",116		},117		{118			name:       "from func main to the end",119			readFile:   read(helloTest, nil),120			sourceFile: "main.go",121			cmd:        ".code main.go /func main/,",122			Code: Code{123				Ext:      ".go",124				FileName: "main.go",125				Play:     false,126				Raw:      []byte("func main() {\n\tfmt.Println(\"hello, test\")\n}"),127				Text:     "<pre><span num=\"6\">func main() {</span>\n<span num=\"7\">    fmt.Println(&#34;hello, test&#34;)</span>\n<span num=\"8\">}</span>\n</pre>",128			},129		},130		{131			name:       "just func main",132			readFile:   read(helloTest, nil),133			sourceFile: "main.go",134			cmd:        ".code main.go /func main/",135			Code: Code{136				Ext:      ".go",137				FileName: "main.go",138				Play:     false,139				Raw:      []byte("func main() {"),140				Text:     "<pre><span num=\"6\">func main() {</span>\n</pre>",141			},142		},143		{144			name:       "bad address",145			readFile:   read(helloTest, nil),146			sourceFile: "main.go",147			cmd:        ".code main.go /function main/",148			err:        "main.go:0: no match for function main",149		},150		{151			name:       "all code with  numbers",152			readFile:   read(helloTest, nil),153			sourceFile: "main.go",154			cmd:        ".code -numbers main.go",155			Code: Code{156				Ext:      ".go",157				FileName: "main.go",158				Raw:      helloTest,159				// Replacing the first "<pre>"160				Text: "<pre class=\"numbers\">" + helloTestHTML[6:],161			},162		},163		{164			name:       "all code editable",165			readFile:   read(helloTest, nil),166			sourceFile: "main.go",167			cmd:        ".code -edit main.go",168			Code: Code{169				Ext:      ".go",170				FileName: "main.go",171				Raw:      helloTest,172				Text:     "<pre contenteditable=\"true\" spellcheck=\"false\">" + helloTestHTML[6:],173			},174		},175	}176	trimHTML := func(t template.HTML) string { return strings.TrimSpace(string(t)) }177	trimBytes := func(b []byte) string { return strings.TrimSpace(string(b)) }178	for _, tt := range tests {179		ctx := &Context{tt.readFile}180		e, err := parseCode(ctx, tt.sourceFile, 0, tt.cmd)181		if err != nil {182			if tt.err == "" {183				t.Errorf("%s: unexpected error %v", tt.name, err)184			} else if !strings.Contains(err.Error(), tt.err) {185				t.Errorf("%s: expected error %s; got %v", tt.name, tt.err, err)186			}187			continue188		}189		if tt.err != "" {190			t.Errorf("%s: expected error %s; but got none", tt.name, tt.err)191			continue192		}193		c, ok := e.(Code)194		if !ok {195			t.Errorf("%s: expected a Code value; got %T", tt.name, e)196			continue197		}198		if c.FileName != tt.FileName {199			t.Errorf("%s: expected FileName %s; got %s", tt.name, tt.FileName, c.FileName)200		}201		if c.Ext != tt.Ext {202			t.Errorf("%s: expected Ext %s; got %s", tt.name, tt.Ext, c.Ext)203		}204		if c.Play != tt.Play {205			t.Errorf("%s: expected Play %v; got %v", tt.name, tt.Play, c.Play)206		}207		if got, wants := trimBytes(c.Raw), trimBytes(tt.Raw); got != wants {208			t.Errorf("%s: expected Raw \n%q\n; got \n%q\n", tt.name, wants, got)209		}210		if got, wants := trimHTML(c.Text), trimHTML(tt.Text); got != wants {211			t.Errorf("%s: expected Text \n%q\n; got \n%q\n", tt.name, wants, got)212		}213	}214}...

...5	"testing"6)7func TestInsert(t *testing.T) {8	// read testdata into memory9	basic, _ := os.ReadFile("testdata/basic.md")10	basicToc, _ := os.ReadFile("testdata/basic_toc.md")11	special, _ := os.ReadFile("testdata/special.md")12	specialToc, _ := os.ReadFile("testdata/special_toc.md")13	repeat, _ := os.ReadFile("testdata/repeat.md")14	repeatToc, _ := os.ReadFile("testdata/repeat_toc.md")15	codeblock, _ := os.ReadFile("testdata/codeblock.md")16	codeblockToc, _ := os.ReadFile("testdata/codeblock_toc.md")17	ignore, _ := os.ReadFile("testdata/ignore.md")18	ignoreToc, _ := os.ReadFile("testdata/ignore_toc.md")19	customHeading, _ := os.ReadFile("testdata/custom_heading.md")20	customHeadingToc, _ := os.ReadFile("testdata/custom_heading_toc.md")21	tt := []struct {22		name    string23		in      []byte24		cfg     *Config25		want    []byte26		wantErr error27	}{28		{"basic", basic, DefaultConfig, basicToc, nil},29		{"special", special, DefaultConfig, specialToc, nil},30		{"repeat", repeat, DefaultConfig, repeatToc, nil},31		{"code block", codeblock, DefaultConfig, codeblockToc, nil},32		{"ignore", ignore, DefaultConfig, ignoreToc, nil},33		{"existing without force", basicToc, DefaultConfig, nil, ErrExistingToc},34		{"existing with force", basicToc, &Config{Force: true}, basicToc, nil},...

1import (2func main() {3    data, err := ioutil.ReadFile("test.txt")4    if err != nil {5        fmt.Println("File reading error", err)6    }7    fmt.Println("Contents of file:", string(data))8}9import (10func main() {11    data, err := ioutil.ReadFile("test.txt")12    if err != nil {13        fmt.Println("File reading error", err)14    }15    fmt.Println("Contents of file:", string(data))16}17import (18func main() {19    data, err := ioutil.ReadFile("test.txt")20    if err != nil {21        fmt.Println("File reading error", err)22    }23    fmt.Println("Contents of file:", string(data))24}25import (26func main() {27    data, err := ioutil.ReadFile("test.txt")28    if err != nil {29        fmt.Println("File reading error", err)30    }31    fmt.Println("Contents of file:", string(data))32}33import (34func main() {35    data, err := ioutil.ReadFile("test.txt")36    if err != nil {37        fmt.Println("File reading error", err)38    }39    fmt.Println("Contents of file:", string(data))40}41import (42func main() {43    data, err := ioutil.ReadFile("test.txt")44    if err != nil {45        fmt.Println("File reading error", err)46    }47    fmt.Println("Contents of file:", string(data))48}49import (

1import (2func main() {3    content, err := ioutil.ReadFile("test.txt")4    if err != nil {5        log.Fatal(err)6    }7    fmt.Printf("File contents: %s", content)8}9import (10func main() {11    data := []byte("This is a test file.")12    err := ioutil.WriteFile("test.txt", data, 0644)13    if err != nil {14        log.Fatal(err)15    }16    fmt.Println("File created successfully")17}18import (19func main() {20    file, err := ioutil.TempFile("/tmp", "test")21    if err != nil {22        log.Fatal(err)23    }24    fmt.Println("Temp file name: ", file.Name())25}26import (27func main() {28    dir, err := ioutil.TempDir("/tmp", "test")29    if err != nil {30        log.Fatal(err)31    }32    fmt.Println("Temp directory name: ", dir)33}34import (

1import (2func main() {3    data, err := ioutil.ReadFile("test.txt")4    if err != nil {5        fmt.Println("File reading error", err)6    }7    fmt.Println("Contents of file:", string(data))8}9import (10func main() {11    data, err := ioutil.ReadFile("test.txt")12    if err != nil {13        fmt.Println("File reading error", err)14    }15    fmt.Println("Contents of file:", data)16}17import (18func main() {19    data, err := ioutil.ReadAll("test.txt")20    if err != nil {21        fmt.Println("File reading error", err)22    }

1import (2func main() {3    data, err := ioutil.ReadFile("test.txt")4    if err != nil {5        fmt.Println("File reading error", err)6    }7    fmt.Println("Contents of file:", string(data))8}9import (10func main() {11    data := []byte("Hello, World!")12    err := ioutil.WriteFile("test.txt", data, 0644)13    if err != nil {14        fmt.Println("Error writing to file:", err)15    }16}17import (18func main() {19    data := []byte("Hello, World!")20    err := ioutil.WriteFile("test.txt", data, 0644)21    if err != nil {22        fmt.Println("Error writing to file:", err)23    }24}25import (26func main() {27    files, err := ioutil.ReadDir("./")28    if err != nil {29        fmt.Println("Error reading directory:", err)30    }31    for _, f := range files {32        fmt.Println(f.Name())33    }34}

1import (2func main() {3    fmt.Println("Hello, playground")4    data, err := ioutil.ReadFile("test.txt")5    if err != nil {6        fmt.Println("File reading error", err)7    }8    fmt.Println("Contents of file:", string(data))9}10import (11func main() {12    fmt.Println("Hello, playground")13    data := []byte("Hello World")14    err := ioutil.WriteFile("test.txt", data, 0644)15    if err != nil {16        fmt.Println("File writing error", err)17    }18    fmt.Println("Data written to file successfully")19}

1import (2func main() {3	fmt.Println("Reading from file")4	data, err := ioutil.ReadFile("test.txt")5	if err != nil {6		fmt.Println("File reading error", err)7	}8	fmt.Println("Contents of file:", string(data))9}10import (11func main() {12	fmt.Println("Reading from file")13	file, err := os.Open("test.txt")14	if err != nil {15		fmt.Println("File reading error", err)16	}17	defer file.Close()18	fileinfo, err := file.Stat()19	if err != nil {20		fmt.Println("File reading error", err)21	}22	filesize := fileinfo.Size()23	buffer := make([]byte, filesize)24	bytesread, err := file.Read(buffer)25	if err != nil {26		fmt.Println("File reading error", err)27	}28	fmt.Println("Bytes read:", bytesread)29	fmt.Println("bytestream to string:", string(buffer))30}31import (32func main() {33	fmt.Println("Reading from file")34	file, err := os.Open("test.txt")35	if err != nil {36		fmt.Println("File reading error", err)37	}38	defer file.Close()39	fileinfo, err := file.Stat()40	if err != nil {41		fmt.Println("File reading error", err)42	}43	filesize := fileinfo.Size()44	buffer := make([]byte, filesize)45	bytesread, err := file.ReadAt(buffer, 0)46	if err != nil {47		fmt.Println("File reading error", err)48	}49	fmt.Println("Bytes read:", bytesread)50	fmt.Println("bytestream to string:", string(buffer))51}52import (53func main() {54	fmt.Println("Reading from file")55	files, err := ioutil.ReadDir(".")56	if err != nil {57		fmt.Println(err)58	}59	for _, file := range files {60		fmt.Println(file.Name())61	}62}

1import (2func main() {3	data, err := ioutil.ReadFile("test.txt")4	if err != nil {5		fmt.Println("File reading error", err)6	}7	fmt.Println("Contents of file:", string(data))8}9func WriteFile(filename string, data []byte, perm os.FileMode) error10import (11func main() {12	err := ioutil.WriteFile("test.txt", []byte("Hello World!"), 0644)13	if err != nil {14		fmt.Println("File writing error", err)15	}16	fmt.Println("Data written to file successfully")17}18func ReadDir(dirname string) ([]os.FileInfo, error)19import (20func main() {21	files, err := ioutil.ReadDir(".")22	if err != nil {23		fmt.Println(err)24	}25	for _, f := range files {26		fmt.Println(f.Name())27	}28}