allowing specifying of multiple mainModules (#48)

* initial commit

Signed-off-by: RinkiyaKeDad <[email protected]>

* made code changes need to test more

Signed-off-by: RinkiyaKeDad <[email protected]>

* reverted getDepInfo function signature

Signed-off-by: RinkiyaKeDad <[email protected]>

* change -m flag help message

Signed-off-by: RinkiyaKeDad <[email protected]>

* fixed wrong max depth error

Signed-off-by: RinkiyaKeDad <[email protected]>

* updated description of max length of deps

Signed-off-by: RinkiyaKeDad <[email protected]>

Author: RinkiyaKeDad

cmd/cycles.go

@@ -31,10 +31,10 @@ var cyclesCmd = &cobra.Command{
 	Short: "Prints cycles in dependency chains.",
 	Long:  `Will show all the cycles in the dependencies of the project.`,
 	RunE: func(cmd *cobra.Command, args []string) error {
-		overview := getDepInfo()
+		overview := getDepInfo(nil)
 		var cycleChains []Chain
 		var temp Chain
-		getCycleChains(overview.MainModuleName, overview.Graph, temp, &cycleChains)
+		getCycleChains(overview.MainModules[0], overview.Graph, temp, &cycleChains)
 		cycles := getCycles(cycleChains)
 
 		if !jsonOutputCycles {

cmd/graph.go

@@ -34,7 +34,7 @@ var graphCmd = &cobra.Command{
 	For example to generate a svg image use:
 	twopi -Tsvg -o dag.svg graph.dot`,
 	RunE: func(cmd *cobra.Command, args []string) error {
-		overview := getDepInfo()
+		overview := getDepInfo(nil)
 		// strict ensures that there is only one edge between two vertices
 		// overlap = false ensures the vertices don't overlap
 		fileContents := "strict digraph {\ngraph [overlap=false];\n"
@@ -43,7 +43,7 @@ var graphCmd = &cobra.Command{
 		if dep != "" {
 			var chains []Chain
 			var temp Chain
-			getAllChains(overview.MainModuleName, overview.Graph, temp, &chains)
+			getAllChains(overview.MainModules[0], overview.Graph, temp, &chains)
 			fileContents += getFileContentsForSingleDep(chains, dep)
 		} else {
 			fileContents += getFileContentsForAllDeps(overview)
@@ -106,9 +106,9 @@ func getFileContentsForSingleDep(chains []Chain, dep string) string {
 func getFileContentsForAllDeps(overview *DependencyOverview) string {
 
 	// color the main module as yellow
-	data := colorMainNode(overview.MainModuleName)
-	allDeps := getAllDeps(overview.Graph[overview.MainModuleName], overview.TransDepList)
-	allDeps = append(allDeps, overview.MainModuleName)
+	data := colorMainNode(overview.MainModules[0])
+	allDeps := getAllDeps(overview.DirectDepList, overview.TransDepList)
+	allDeps = append(allDeps, overview.MainModules[0])
 	sort.Strings(allDeps)
 	for _, dep := range allDeps {
 		_, ok := overview.Graph[dep]
@@ -117,7 +117,7 @@ func getFileContentsForAllDeps(overview *DependencyOverview) string {
 		}
 		// main module can never be a neighbour
 		for _, neighbour := range overview.Graph[dep] {
-			if dep == overview.MainModuleName {
+			if dep == overview.MainModules[0] {
 				// for the main module use a colored node
 				data += fmt.Sprintf("\"MainNode\" -> \"%s\"\n", neighbour)
 			} else {

cmd/list.go

@@ -29,9 +29,9 @@ var listCmd = &cobra.Command{
 	Long: `Gives a list of all the dependencies of the project. 
 	These include both direct as well as transitive dependencies.`,
 	RunE: func(cmd *cobra.Command, args []string) error {
-		depGraph := getDepInfo()
+		depGraph := getDepInfo(nil)
 		fmt.Println("List of all dependencies:")
-		allDeps := getAllDeps(depGraph.Graph[depGraph.MainModuleName], depGraph.TransDepList)
+		allDeps := getAllDeps(depGraph.DirectDepList, depGraph.TransDepList)
 		printDeps(allDeps)
 		return nil
 	},

cmd/stats.go

@@ -25,6 +25,7 @@ import (
 
 var jsonOutput bool
 var verbose bool
+var mainModules []string
 
 type Chain []string
 
@@ -33,22 +34,23 @@ var statsCmd = &cobra.Command{
 	Use:   "stats",
 	Short: "Shows metrics about dependency chains",
 	Long: `Provides the following metrics:
-	1. Total Dependencies: Total number of dependencies of the project
-	2. Max Depth of Dependencies: Number of dependencies in the longest dependency chain
-	3. Transitive Dependencies: Total number of transitive dependencies (dependencies which are not direct dependencies of the project)`,
+	1. Direct Dependencies: Total number of dependencies required by the mainModule(s) directly
+	2. Transitive Dependencies: Total number of transitive dependencies (dependencies which are further needed by direct dependencies of the project)
+	3. Total Dependencies: Total number of dependencies of the mainModule(s)
+	4. Max Depth of Dependencies: Length of the longest chain starting from the first mainModule; defaults to length from the first module encountered in "go mod graph" output`,
 	RunE: func(cmd *cobra.Command, args []string) error {
-		depGraph := getDepInfo()
+		depGraph := getDepInfo(mainModules)
 
 		// get the longest chain
 		var longestChain Chain
 		var temp Chain
-		getLongestChain(depGraph.MainModuleName, depGraph.Graph, temp, &longestChain)
+		getLongestChain(depGraph.MainModules[0], depGraph.Graph, temp, &longestChain)
 
 		// get values
 		maxDepth := len(longestChain)
-		directDeps := len(depGraph.Graph[depGraph.MainModuleName])
-		totalDeps := len(getAllDeps(depGraph.Graph[depGraph.MainModuleName], depGraph.TransDepList))
+		directDeps := len(depGraph.DirectDepList)
 		transitiveDeps := len(depGraph.TransDepList)
+		totalDeps := len(getAllDeps(depGraph.DirectDepList, depGraph.TransDepList))
 
 		if !jsonOutput {
 			fmt.Printf("Direct Dependencies: %d \n", directDeps)
@@ -59,7 +61,7 @@ var statsCmd = &cobra.Command{
 
 		if verbose {
 			fmt.Println("All dependencies:")
-			printDeps(append(depGraph.Graph[depGraph.MainModuleName], depGraph.TransDepList...))
+			printDeps(getAllDeps(depGraph.DirectDepList, depGraph.TransDepList))
 		}
 
 		// print the longest chain
@@ -118,4 +120,5 @@ func init() {
 	rootCmd.AddCommand(statsCmd)
 	statsCmd.Flags().BoolVarP(&verbose, "verbose", "v", false, "Get additional details")
 	statsCmd.Flags().BoolVarP(&jsonOutput, "json", "j", false, "Get the output in JSON format")
+	statsCmd.Flags().StringSliceVarP(&mainModules, "mainModules", "m", []string{}, "Enter modules whose dependencies should be considered direct dependencies; defaults to the first module encountered in `go mod graph` output")
 }

cmd/utils.go

@@ -34,13 +34,16 @@ func printChain(slice []string) {
 type DependencyOverview struct {
 	// Dependency graph edges modelled as node plus adjacency nodes
 	Graph map[string][]string
+	// List of all direct dependencies
+	DirectDepList []string
 	// List of all transitive dependencies
 	TransDepList []string
 	// Name of the module from which the dependencies are computed
-	MainModuleName string
+	MainModules []string
 }
 
-func getDepInfo() *DependencyOverview {
+func getDepInfo(mainModules []string) *DependencyOverview {
+	depGraph := DependencyOverview{MainModules: mainModules}
 	// get output of "go mod graph" in a string
 	goModGraph := exec.Command("go", "mod", "graph")
 	goModGraphOutput, err := goModGraph.Output()
@@ -50,13 +53,9 @@ func getDepInfo() *DependencyOverview {
 	goModGraphOutputString := string(goModGraphOutput)
 
 	// create a graph of dependencies from that output
-	depGraph := make(map[string][]string)
+	graph := make(map[string][]string)
 	scanner := bufio.NewScanner(strings.NewReader(goModGraphOutputString))
 
-	// transDeps will store all the transitive dependencies
-	var transDeps []string
-	mainModule := "notset"
-
 	for scanner.Scan() {
 		line := scanner.Text()
 		words := strings.Fields(line)
@@ -65,27 +64,30 @@ func getDepInfo() *DependencyOverview {
 		words[1] = (strings.Split(words[1], "@"))[0]
 
 		// we don't want to add the same dep again
-		if !contains(depGraph[words[0]], words[1]) {
-			depGraph[words[0]] = append(depGraph[words[0]], words[1])
+		if !contains(graph[words[0]], words[1]) {
+			graph[words[0]] = append(graph[words[0]], words[1])
 		}
 
-		if mainModule == "notset" {
-			mainModule = words[0]
+		if len(depGraph.MainModules) == 0 {
+			depGraph.MainModules = append(depGraph.MainModules, words[0])
 		}
 
-		// anything where the LHS is not mainModule
-		// is a transitive dependency
-		if words[0] != mainModule {
-			if !contains(transDeps, words[1]) {
-				transDeps = append(transDeps, words[1])
+		// if the LHS is a mainModule
+		// then RHS is a direct dep else transitive dep
+		if contains(depGraph.MainModules, words[0]) && contains(depGraph.MainModules, words[1]) {
+			continue
+		} else if contains(depGraph.MainModules, words[0]) {
+			if !contains(depGraph.DirectDepList, words[1]) {
+				depGraph.DirectDepList = append(depGraph.DirectDepList, words[1])
+			}
+		} else if !contains(depGraph.MainModules, words[0]) {
+			if !contains(depGraph.TransDepList, words[1]) {
+				depGraph.TransDepList = append(depGraph.TransDepList, words[1])
 			}
 		}
 	}
-	return &DependencyOverview{
-		Graph:          depGraph,
-		TransDepList:   transDeps,
-		MainModuleName: mainModule,
-	}
+	depGraph.Graph = graph
+	return &depGraph
 }
 
 func printDeps(deps []string) {
@@ -97,6 +99,7 @@ func printDeps(deps []string) {
 	fmt.Println()
 }
 
+// we need this since a dependency can be both a direct and an indirect dependency
 func getAllDeps(directDeps []string, transDeps []string) []string {
 	var allDeps []string
 	for _, dep := range directDeps {

cmd/utils_test.go

@@ -45,10 +45,13 @@ func Test_getChains_simple(t *testing.T) {
 	graph["F"] = []string{"H"}
 
 	transDeps := []string{"E", "G", "F", "H"}
+	directDeps := []string{"B", "C", "D"}
+	mainModules := []string{"A"}
 	overview := &DependencyOverview{
-		Graph:          graph,
-		TransDepList:   transDeps,
-		MainModuleName: "A",
+		Graph:         graph,
+		TransDepList:  transDeps,
+		DirectDepList: directDeps,
+		MainModules:   mainModules,
 	}
 
 	var cycleChains []Chain
@@ -137,10 +140,13 @@ func Test_getChains_cycle(t *testing.T) {
 	graph["H"] = []string{"D"}
 
 	transDeps := []string{"D", "E", "F", "G", "H"}
+	directDeps := []string{"B", "C"}
+	mainModules := []string{"A"}
 	overview := &DependencyOverview{
-		Graph:          graph,
-		TransDepList:   transDeps,
-		MainModuleName: "A",
+		Graph:         graph,
+		TransDepList:  transDeps,
+		DirectDepList: directDeps,
+		MainModules:   mainModules,
 	}
 
 	var cycleChains []Chain
@@ -228,11 +234,13 @@ func Test_getChains_cycle_2(t *testing.T) {
 	graph["D"] = []string{"C"}
 
 	transDeps := []string{"C", "B", "E", "F", "D"}
-
+	directDeps := []string{"B", "C"}
+	mainModules := []string{"A"}
 	overview := &DependencyOverview{
-		Graph:          graph,
-		TransDepList:   transDeps,
-		MainModuleName: "A",
+		Graph:         graph,
+		TransDepList:  transDeps,
+		DirectDepList: directDeps,
+		MainModules:   mainModules,
 	}
 
 	var cycleChains []Chain