Fix golint errors and gofmt

internal/cards/calc.go

@@ -44,6 +44,8 @@ func NewCalcCard(query, _ string) Card {
 	return &CalcCard{query: query, useFunc: true}
 }
 
+// Matches determines whether a query matches the requirements
+// fot CalcCard and determines which function to run with what arguments
 func (cc *CalcCard) Matches() bool {
 	// If query has solve prefix
 	if strings.HasPrefix(cc.query, "solve") {
@@ -106,6 +108,7 @@ func (cc *CalcCard) Matches() bool {
 	return false
 }
 
+// StripKey removes all key words related to CalcCard
 func (cc *CalcCard) StripKey() string {
 	// Compile regex for words to be removed
 	trimRgx := regexp.MustCompile(`^(.*?)solve|integrate|integral(?: of)?|diff|differentiate|derivative(?: of)?|derive|calculate(.*)$`)
@@ -113,6 +116,7 @@ func (cc *CalcCard) StripKey() string {
 	return trimRgx.ReplaceAllString(cc.query, "${1}${2}")
 }
 
+// Content returns the solveRenderScript with the given input
 func (cc *CalcCard) Content() template.HTML {
 	var input string
 	// If function is being used
@@ -130,22 +134,29 @@ func (cc *CalcCard) Content() template.HTML {
 	))
 }
 
+// Footer returns empty string because CalcCard has no footer
 func (cc *CalcCard) Footer() template.HTML {
 	return ""
 }
 
+// Returned always returns true since CalcCard is a frontend
+// card and it is thus impossible to determine whether
+// the query gets an answer
 func (cc *CalcCard) Returned() bool {
 	return true
 }
 
+// RunQuery returns nil as CalcCard is a frontend card
 func (cc *CalcCard) RunQuery() error {
 	return nil
 }
 
+// Title for CalcCard is "Calculation"
 func (cc *CalcCard) Title() string {
 	return "Calculation"
 }
 
+// Head returns the extra head tags required for CalcCard
 func (cc *CalcCard) Head() template.HTML {
 	return calcExtraHead
 }

internal/cards/cards.go

@@ -1,13 +1,10 @@
 package cards
 
 import (
-	"errors"
 	"html/template"
 	"sort"
 )
 
-var ErrCardRegistered = errors.New("card with that name has already been registered")
-
 // cardRegistration represents a card that has been registered
 type cardRegistration struct {
 	name     string
@@ -79,7 +76,7 @@ func GetCard(query, userAgent string) Card {
 	for _, cardReg := range cards {
 		// Create new card
 		card := cardReg.newFn(query, userAgent)
-		// If card matches, return it 
+		// If card matches, return it
 		if card.Matches() {
 			return card
 		}

internal/cards/ddg.go

@@ -39,7 +39,7 @@ type DDGInstAns struct {
 	AnswerType     string
 }
 
-// NewDDGCard isa NewCardFunc that creates a new DDGCard
+// NewDDGCard is a NewCardFunc that creates a new DDGCard
 func NewDDGCard(query, userAgent string) Card {
 	return &DDGCard{
 		query:     url.QueryEscape(query),
@@ -68,7 +68,7 @@ func (ddg *DDGCard) RunQuery() error {
 		return err
 	}
 
-	// Decode response into repsonse struct
+	// Decode response into response struct
 	err = json.NewDecoder(res.Body).Decode(&ddg.resp)
 	if err != nil {
 		return err
@@ -77,30 +77,38 @@ func (ddg *DDGCard) RunQuery() error {
 	return nil
 }
 
+// Returned checks if abstract is empty.
+// If it is, query returned no result.
 func (ddg *DDGCard) Returned() bool {
 	// Value was returned if abstract is not empty
 	return ddg.resp.Abstract != ""
 }
 
+// Matches always returns true as there are no keys
 func (ddg *DDGCard) Matches() bool {
-	// Everything matches since there are no keys
 	return true
 }
 
+// StripKey returns the query as there are no keys
 func (ddg *DDGCard) StripKey() string {
 	// No key to strip, so return query
 	return ddg.query
 }
 
+// Title returns the instant answer heading
 func (ddg *DDGCard) Title() string {
 	return ddg.resp.Heading
 }
 
+// Content returns the instant answer abstract with
+// DuckDuckGo attibution
 func (ddg *DDGCard) Content() template.HTML {
 	// Return abstract with attribution
 	return template.HTML(ddg.resp.Abstract + fmt.Sprintf(ddgAttribution, ddg.query))
 }
 
+// Footer returns a footer containing URL and name of source
+// gotten from instant answer API
 func (ddg *DDGCard) Footer() template.HTML {
 	// Return footer with abstract url and source
 	return template.HTML(fmt.Sprintf(
@@ -110,6 +118,8 @@ func (ddg *DDGCard) Footer() template.HTML {
 	))
 }
 
+// Head returns an empty string as no extra tags are reuired
+// for DDGCard
 func (ddg *DDGCard) Head() template.HTML {
 	return ""
 }

internal/cards/metaweather.go

@@ -166,16 +166,21 @@ func (mc *MetaweatherCard) RunQuery() error {
 	return nil
 }
 
+// Returned checks whether no location was found or response
+// said not found.
 func (mc *MetaweatherCard) Returned() bool {
 	return len(mc.location) > 0 && mc.resp.Detail != "Not found."
 }
 
+// Matches determines whether the query matches the keys for
+// MetaweatherCard
 func (mc *MetaweatherCard) Matches() bool {
 	return strings.HasPrefix(mc.query, "weather in") ||
 		strings.HasPrefix(mc.query, "weather") ||
 		strings.HasSuffix(mc.query, "weather")
 }
 
+// StripKey removes keys related to MetaweatherCard
 func (mc *MetaweatherCard) StripKey() string {
 	query := strings.TrimPrefix(mc.query, "weather in")
 	query = strings.TrimPrefix(query, "weather")
@@ -183,6 +188,7 @@ func (mc *MetaweatherCard) StripKey() string {
 	return strings.TrimSpace(query)
 }
 
+// Content returns metaweatherContent with all information added
 func (mc *MetaweatherCard) Content() template.HTML {
 	return template.HTML(fmt.Sprintf(
 		metaweatherContent,
@@ -213,15 +219,18 @@ func (mc *MetaweatherCard) Content() template.HTML {
 	))
 }
 
+// Title of MetaweatherCard is "Weather"
 func (mc *MetaweatherCard) Title() string {
 	return "Weather"
 }
 
+// Footer returns a footer with a link to metaweather
 func (mc *MetaweatherCard) Footer() template.HTML {
-	// Return footer with link to metaweather
 	return `<div class="card-footer"><a class="card-footer-item" href="https://www.metaweather.com/">Metaweather</a></div>`
 }
 
+// Head returns an empty string as no extra head tags
+// are required for MetaweatherCard
 func (mc *MetaweatherCard) Head() template.HTML {
 	return ""
 }

internal/cards/plot.go

@@ -43,12 +43,14 @@ func NewPlotCard(query, _ string) Card {
 	return &PlotCard{query: query}
 }
 
+// Matches checks if the query matches the rules for PlotCard
 func (pc *PlotCard) Matches() bool {
 	return strings.HasPrefix(pc.query, "plot") ||
 		strings.HasPrefix(pc.query, "graph") ||
 		strings.HasPrefix(pc.query, "draw")
 }
 
+// StripKey removes all keys related to PlotCard
 func (pc *PlotCard) StripKey() string {
 	query := strings.TrimPrefix(pc.query, "plot")
 	query = strings.TrimPrefix(query, "graph")
@@ -56,6 +58,7 @@ func (pc *PlotCard) StripKey() string {
 	return strings.TrimSpace(query)
 }
 
+// Content returns plot script with given input
 func (pc *PlotCard) Content() template.HTML {
 	return template.HTML(fmt.Sprintf(
 		plotScript,
@@ -63,27 +66,28 @@ func (pc *PlotCard) Content() template.HTML {
 	))
 }
 
-// Since this card is frontend, this cannot be checked.
-// Therefore, it will always return true.
+// Returned will alwats return true because
+// this card is frontend, and this cannot be checked.
 func (pc *PlotCard) Returned() bool {
 	return true
 }
 
+// Title generates a title formatted as "Plot (<eqation>)"
 func (pc *PlotCard) Title() string {
 	return "Plot (" + pc.StripKey() + ")"
 }
 
+// Head returns extra head tags for PlotCard
 func (pc *PlotCard) Head() template.HTML {
 	return plotExtraHead
 }
 
+// Footer returns an empty string as PlotCard has no footer
 func (pc *PlotCard) Footer() template.HTML {
 	return ""
 }
 
-
+// RunQuery returns nil as PlotCard is a frontend card
 func (pc *PlotCard) RunQuery() error {
 	return nil
 }
-
-

main.go

@@ -66,6 +66,7 @@ type TmplContext struct {
 	Card    cards.Card
 }
 
+// ErrTmplContext represents context passed to an error template
 type ErrTmplContext struct {
 	BaseContext
 	Error     string
@@ -74,6 +75,7 @@ type ErrTmplContext struct {
 	Status    int
 }
 
+// BaseContext is the common context between all templates
 type BaseContext struct {
 	LoadTime time.Duration
 }
@@ -252,7 +254,7 @@ func main() {
 
 	// Join address and port from config
 	addr := net.JoinHostPort(viper.GetString("server.addr"), viper.GetString("server.port"))
-	
+
 	// Log server starting with address
 	log.Info().Str("address", addr).Msg("Starting HTTP server")
 	// Start server

search/web/bing.go

@@ -9,6 +9,7 @@ import (
 
 var bingURL = urlMustParse("https://www.bing.com/search?count=10")
 
+// Bing represents the Bing search engine
 type Bing struct {
 	keyword   string
 	userAgent string
@@ -18,29 +19,37 @@ type Bing struct {
 	baseSel   *goquery.Selection
 }
 
+// SetKeyword sets the keyword for searching
 func (b *Bing) SetKeyword(keyword string) {
 	b.keyword = keyword
 }
 
+// SetPage sets the page number for searching
 func (b *Bing) SetPage(page int) {
 	b.first = page * 10
 }
 
+// SetUserAgent sets the user agent to use for the request
 func (b *Bing) SetUserAgent(ua string) {
 	b.userAgent = ua
 }
 
+// Init runs requests for Bing search engine
 func (b *Bing) Init() error {
+	// Copy URL so it can be changed
 	initURL := copyURL(bingURL)
 	query := initURL.Query()
+	// Set query
 	query.Set("q", b.keyword)
 	if b.first > 0 {
 		query.Set("first", strconv.Itoa(b.first))
 	} else {
 		query.Set("first", "1")
 	}
+	// Update URL query parameters
 	initURL.RawQuery = query.Encode()
 
+	// Create new request for modified URL
 	req, err := http.NewRequest(
 		http.MethodGet,
 		initURL.String(),
@@ -49,17 +58,21 @@ func (b *Bing) Init() error {
 	if err != nil {
 		return err
 	}
+	// If no user agent, use default
 	if b.userAgent == "" {
 		b.userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36"
 	}
+	// Set request user agent
 	req.Header.Set("User-Agent", b.userAgent)
 
+	// Perform request
 	res, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return err
 	}
 	defer res.Body.Close()
 
+	// Create new goquery document
 	doc, err := goquery.NewDocumentFromReader(res.Body)
 	if err != nil {
 		return err
@@ -70,6 +83,7 @@ func (b *Bing) Init() error {
 	return nil
 }
 
+// Each runs eachCb with the index of each search result
 func (b *Bing) Each(eachCb func(int) error) error {
 	for i := 0; i < b.baseSel.Length(); i++ {
 		err := eachCb(i)
@@ -80,18 +94,22 @@ func (b *Bing) Each(eachCb func(int) error) error {
 	return nil
 }
 
+// Title returns the title of the search result corresponding to i
 func (b *Bing) Title(i int) (string, error) {
 	return get(b.baseSel, i).ChildrenFiltered("h2").Children().First().Text(), nil
 }
 
+// Link returns the link to the search result corresponding to i
 func (b *Bing) Link(i int) (string, error) {
 	return get(b.baseSel, i).ChildrenFiltered("h2").Children().First().AttrOr("href", ""), nil
 }
 
+// Desc returns the description of the search result corresponding to i
 func (b *Bing) Desc(i int) (string, error) {
 	return get(b.baseSel, i).ChildrenFiltered(".b_caption").Children().Last().Text(), nil
 }
 
+// Name returns "bing"
 func (b *Bing) Name() string {
 	return "bing"
 }

search/web/ddg.go

@@ -12,6 +12,7 @@ var ddgURL = urlMustParse("https://html.duckduckgo.com/html")
 
 const uddgPrefix = "//duckduckgo.com/l/?uddg="
 
+// DDG represents the DuckDuckGo search engine
 type DDG struct {
 	keyword   string
 	userAgent string
@@ -21,28 +22,37 @@ type DDG struct {
 	baseSel   *goquery.Selection
 }
 
+// SetKeyword sets the keyword for searching
 func (d *DDG) SetKeyword(keyword string) {
 	d.keyword = keyword
 }
 
+// SetPage sets the page number for searching
 func (d *DDG) SetPage(page int) {
 	d.page = page * 30
 }
 
+// SetUserAgent sets the user agent for the request
 func (d *DDG) SetUserAgent(ua string) {
-	d.userAgent = "Opera/9.80 (Windows NT 5.1; U; zh-tw) Presto/2.8.131 Version/11.10" //ua
+	d.userAgent = ua
 }
 
+// Init runs requests for the DuckDuckGo search engine
 func (d *DDG) Init() error {
+	// Copy URL so that it can be changed
 	initURL := copyURL(ddgURL)
+	// Get query parameters
 	query := initURL.Query()
+	// Set query
 	query.Set("q", d.keyword)
 	if d.page > 0 {
 		query.Set("s", strconv.Itoa(d.page))
 		query.Set("dc", strconv.Itoa(d.page+1))
 	}
+	// Update URL query
 	initURL.RawQuery = query.Encode()
 
+	// Create new request for modified URL
 	req, err := http.NewRequest(
 		http.MethodGet,
 		initURL.String(),
@@ -51,17 +61,21 @@ func (d *DDG) Init() error {
 	if err != nil {
 		return err
 	}
+	// If user agent empty, use default
 	if d.userAgent == "" {
 		d.userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36"
 	}
+	// Set user agent of request
 	req.Header.Set("User-Agent", d.userAgent)
 
+	// Perform request
 	res, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return err
 	}
 	defer res.Body.Close()
 
+	// Create goquery document from reader
 	doc, err := goquery.NewDocumentFromReader(res.Body)
 	if err != nil {
 		return err
@@ -72,6 +86,7 @@ func (d *DDG) Init() error {
 	return nil
 }
 
+// Each runs eachCb with the index of each search result
 func (d *DDG) Each(eachCb func(int) error) error {
 	for i := 0; i < d.baseSel.Length(); i++ {
 		err := eachCb(i)
@@ -82,10 +97,12 @@ func (d *DDG) Each(eachCb func(int) error) error {
 	return nil
 }
 
+// Title returns the title of the search result corresponding to i
 func (d *DDG) Title(i int) (string, error) {
 	return strings.TrimSpace(get(d.baseSel, i).Children().First().ChildrenFiltered("h2").Text()), nil
 }
 
+// Link returns the link to the search result corresponding to i
 func (d *DDG) Link(i int) (string, error) {
 	link := get(d.baseSel, i).Children().First().ChildrenFiltered("a").AttrOr("href", "")
 	if strings.HasPrefix(link, uddgPrefix) {
@@ -94,10 +111,12 @@ func (d *DDG) Link(i int) (string, error) {
 	return link, nil
 }
 
+// Desc returns the description of the search result corresponding to i
 func (d *DDG) Desc(i int) (string, error) {
 	return get(d.baseSel, i).Children().First().ChildrenFiltered("a").Text(), nil
 }
 
+// Name returns "ddg"
 func (d *DDG) Name() string {
 	return "ddg"
 }

search/web/google.go

@@ -10,6 +10,7 @@ import (
 
 var googleURL = urlMustParse("https://www.google.com/search")
 
+// Google represents the Google search engine
 type Google struct {
 	keyword   string
 	userAgent string
@@ -19,24 +20,35 @@ type Google struct {
 	baseSel   *goquery.Selection
 }
 
+// SetKeyword sets the keyword for searching
 func (g *Google) SetKeyword(keyword string) {
 	g.keyword = keyword
 }
 
+// SetPage sets the page number for searching
 func (g *Google) SetPage(page int) {
 	g.page = page * 10
 }
 
+// SetUserAgent sets the user agent for the request
 func (g *Google) SetUserAgent(ua string) {
 	g.userAgent = ua
 }
 
+// Init runs requests for the Google search engine
 func (g *Google) Init() error {
+	// Copy URL so that it can be changed
 	initURL := copyURL(googleURL)
+	// Get query parameters
 	query := initURL.Query()
+	// Set query
 	query.Set("q", g.keyword)
+	// Set starting result (page number)
 	query.Set("start", strconv.Itoa(g.page))
+	// Update URL query
 	initURL.RawQuery = query.Encode()
+
+	// Create new request for modified URL
 	req, err := http.NewRequest(
 		http.MethodGet,
 		initURL.String(),
@@ -45,17 +57,21 @@ func (g *Google) Init() error {
 	if err != nil {
 		return err
 	}
+	// If user agent empty, use default
 	if g.userAgent == "" {
 		g.userAgent = "Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/74.0.3729.169 Safari/537.36"
 	}
+	// Set user agent of request
 	req.Header.Set("User-Agent", g.userAgent)
 
+	// Perform request
 	res, err := http.DefaultClient.Do(req)
 	if err != nil {
 		return err
 	}
 	defer res.Body.Close()
 
+	// Create goquery document from reader
 	doc, err := goquery.NewDocumentFromReader(res.Body)
 	if err != nil {
 		return err
@@ -66,6 +82,7 @@ func (g *Google) Init() error {
 	return nil
 }
 
+// Each runs eachCb with the index of each search result
 func (g *Google) Each(eachCb func(int) error) error {
 	for i := 0; i < g.baseSel.Length(); i++ {
 		err := eachCb(i)
@@ -76,31 +93,38 @@ func (g *Google) Each(eachCb func(int) error) error {
 	return nil
 }
 
+// Title returns the title of the search result corresponding to i
 func (g *Google) Title(i int) (string, error) {
 	return get(g.baseSel, i).Text(), nil
 }
 
+// Link returns the link to the search result corresponding to i
 func (g *Google) Link(i int) (string, error) {
 	return get(g.baseSel, i).Parent().AttrOr("href", ""), nil
 }
 
+// Desc returns the description of the search result corresponding to i
 func (g *Google) Desc(i int) (string, error) {
 	return get(g.baseSel, i).Parent().Parent().Next().Text(), nil
 }
 
+// Name returns "google"
 func (g *Google) Name() string {
 	return "google"
 }
 
+// get gets an element and given index from given selection
 func get(sel *goquery.Selection, i int) *goquery.Selection {
 	return sel.Slice(i, i+1)
 }
 
+// Parse url ignoring error
 func urlMustParse(urlStr string) *url.URL {
 	out, _ := url.Parse(urlStr)
 	return out
 }
 
+// copyURL makes a copy of the url and returns it
 func copyURL(orig *url.URL) *url.URL {
 	newURL := new(url.URL)
 	*newURL = *orig

search/web/search.go

@@ -13,6 +13,7 @@ func init() {
 	http.DefaultClient.Timeout = 5 * time.Second
 }
 
+// Result represents a search result
 type Result struct {
 	Title   string
 	Link    string
@@ -21,6 +22,7 @@ type Result struct {
 	Rank    int
 }
 
+// Engine represents a search engine for web results (not images, shopping, erc.)
 type Engine interface {
 	// Set search keyword for engine
 	SetKeyword(string)
@@ -51,74 +53,95 @@ type Engine interface {
 	Name() string
 }
 
+// Options represents search options
 type Options struct {
 	Keyword   string
 	UserAgent string
 	Page      int
 }
 
+// Search searches the given engines concurrently and returns the results
 func Search(opts Options, engines ...Engine) ([]*Result, error) {
 	var outMtx sync.Mutex
 	var out []*Result
 
+	// Create new error group
 	wg := errgroup.Group{}
+	// For every engine
 	for index, engine := range engines {
+		// Copy index and engine (for goroutine)
 		curIndex, curEngine := index, engine
 		wg.Go(func() error {
-
+			// Set options
 			curEngine.SetKeyword(opts.Keyword)
 			curEngine.SetUserAgent(opts.UserAgent)
 			curEngine.SetPage(opts.Page)
 
+			// Attempt to init engine
 			if err := curEngine.Init(); err != nil {
 				return err
 			}
 
+			// For each result
 			err := curEngine.Each(func(i int) error {
+				// Get result link
 				link, err := curEngine.Link(i)
 				if err != nil {
 					return err
 				}
 
+				// Calculate result rank
 				rank := (curIndex * 100) + i
 
+				// Check if result exists
 				index, exists := linkExists(out, link)
+				// If result already exists
 				if exists {
+					// Add engine to the existing result
 					out[index].Engines = append(out[index].Engines, curEngine.Name())
+					// If the rank is higher than the old one, update it
 					if rank < out[index].Rank {
 						out[index].Rank = rank
 					}
 					return nil
 				}
 
+				// Get result title
 				title, err := curEngine.Title(i)
 				if err != nil {
 					return err
 				}
 
+				// Get result description
 				desc, err := curEngine.Desc(i)
 				if err != nil {
 					return err
 				}
 
+				// If title, link, or description empty, ignore
 				if title == "" || link == "" || desc == "" {
 					return nil
 				}
 
+				// If length of description, truncate
 				if len(desc) > 500 {
 					desc = desc[:500] + "..."
 				}
 
+				// Create result struct
 				result := &Result{
-					Title: title,
-					Link:  link,
-					Desc:  desc,
-					Rank:  rank,
+					Title:   title,
+					Link:    link,
+					Desc:    desc,
+					Rank:    rank,
+					Engines: []string{curEngine.Name()},
 				}
-				result.Engines = append(result.Engines, curEngine.Name())
 
+				// Lock out mutex
 				outMtx.Lock()
+				// Add result to slice
 				out = append(out, result)
+				// Unlock out mutex
 				outMtx.Unlock()
 
 				return nil
@@ -127,6 +150,7 @@ func Search(opts Options, engines ...Engine) ([]*Result, error) {
 				return err
 			}
 
+			// Sort slice by rank
 			sort.Slice(out, func(i, j int) bool {
 				return out[i].Rank < out[j].Rank
 			})
@@ -134,6 +158,7 @@ func Search(opts Options, engines ...Engine) ([]*Result, error) {
 		})
 	}
 
+	// Wait for error group
 	if err := wg.Wait(); err != nil {
 		return out, err
 	}
@@ -141,9 +166,13 @@ func Search(opts Options, engines ...Engine) ([]*Result, error) {
 	return out, nil
 }
 
+// linkExists checks if a link exists in the results
 func linkExists(results []*Result, link string) (int, bool) {
+	// For every result
 	for index, result := range results {
+		// If link is the same as provided
 		if result.Link == link {
+			// Return index with true
 			return index, true
 		}
 	}