feat: implement coarse versioning in go

CONTRIBUTING.md

@@ -97,6 +97,16 @@ By default, this skips long tests, enable them by setting the `LONG_TESTS` varia
 LONG_TESTS=1 make api-server-tests
 ```
 
+There are additional tests for testing coarse version ordering logic for ecosystem version
+parsers. These are tested against the entire OSV database.
+```shell
+# in go/
+# you must generate the list of all versions by running
+./osv/ecosystem/testdata/regen_coarse_test_data.sh
+# then run the tests
+RUN_COARSE_LARGE_TEST=1 go test ./osv/ecosystem -run TestCoarseMonotonicityLarge
+```
+
 ##### Test result generation
 
 Many tests are written using a

go/cmd/extract_versions/main.go

@@ -0,0 +1,126 @@
+// Package main implements a tool to extract unique versions from OSV vulnerabilities zip file.
+package main
+
+import (
+	"archive/zip"
+	"fmt"
+	"io"
+	"maps"
+	"os"
+	"runtime"
+	"slices"
+	"sync"
+
+	"github.com/ossf/osv-schema/bindings/go/osvschema"
+	"google.golang.org/protobuf/encoding/protojson"
+)
+
+func main() {
+	if len(os.Args) != 3 {
+		fmt.Println("Usage: extract_versions <zipfile> <outputfile>")
+		os.Exit(1)
+	}
+	zipFile := os.Args[1]
+	outputFile := os.Args[2]
+
+	zipReader, err := zip.OpenReader(zipFile)
+	if err != nil {
+		panic(err)
+	}
+	defer zipReader.Close()
+
+	versionChan := make(chan string, 1000)
+	var wg sync.WaitGroup
+
+	// Worker pool
+	numWorkers := runtime.NumCPU()
+	fileChan := make(chan *zip.File)
+
+	// Start workers
+	for range numWorkers {
+		wg.Add(1)
+		go func() {
+			defer wg.Done()
+			for file := range fileChan {
+				r, err := file.Open()
+				if err != nil {
+					fmt.Fprintln(os.Stderr, err)
+					continue
+				}
+				bytes, err := io.ReadAll(r)
+				r.Close()
+				if err != nil {
+					fmt.Fprintln(os.Stderr, err)
+					continue
+				}
+				var vuln osvschema.Vulnerability
+				if err := protojson.Unmarshal(bytes, &vuln); err != nil {
+					fmt.Fprintln(os.Stderr, err)
+					continue
+				}
+				for _, affected := range vuln.GetAffected() {
+					for _, version := range affected.GetVersions() {
+						versionChan <- version
+					}
+					for _, ranges := range affected.GetRanges() {
+						if ranges.GetType() == osvschema.Range_GIT {
+							continue
+						}
+						for _, event := range ranges.GetEvents() {
+							if event.GetIntroduced() != "" {
+								versionChan <- event.GetIntroduced()
+							}
+							if event.GetFixed() != "" {
+								versionChan <- event.GetFixed()
+							}
+							if event.GetLastAffected() != "" {
+								versionChan <- event.GetLastAffected()
+							}
+						}
+					}
+				}
+			}
+		}()
+	}
+
+	// Collector
+	allVersions := make(map[string]struct{})
+	doneChan := make(chan struct{})
+	go func() {
+		for v := range versionChan {
+			allVersions[v] = struct{}{}
+		}
+		close(doneChan)
+	}()
+
+	// Feed files to workers
+	for _, file := range zipReader.File {
+		fileChan <- file
+	}
+	close(fileChan)
+
+	// Wait for workers to finish
+	wg.Wait()
+	close(versionChan)
+
+	// Wait for collector to finish
+	<-doneChan
+
+	// Sort versions
+	vers := slices.Sorted(maps.Keys(allVersions))
+
+	// Write to output file
+	f, err := os.Create(outputFile)
+	if err != nil {
+		panic(err)
+	}
+	defer f.Close()
+
+	for _, v := range vers {
+		if _, err := fmt.Fprintln(f, v); err != nil {
+			panic(err)
+		}
+	}
+
+	fmt.Printf("Successfully extracted %d unique versions to %s\n", len(vers), outputFile)
+}

go/osv/ecosystem/.gitignore

@@ -0,0 +1 @@
+testdata/all_versions.txt

go/osv/ecosystem/apk.go

@@ -14,7 +14,11 @@
 
 package ecosystem
 
-import "github.com/google/osv-scalibr/semantic"
+import (
+	"regexp"
+
+	"github.com/google/osv-scalibr/semantic"
+)
 
 // apkEcosystem is an ecosystem for ecosystems using Alpine Package Keeper versioning.
 type apkEcosystem struct{}
@@ -30,7 +34,18 @@ func (e apkEcosystem) Parse(version string) (Version, error) {
 	return SemanticVersionWrapper[semantic.AlpineVersion]{ver}, nil
 }
 
+//nolint:unused
+var apkCoarseVersioner = CoarseVersioner{
+	Separators:    regexp.MustCompile(`[.]`),
+	Truncate:      regexp.MustCompile(`(?:\.0|[_-])`),
+	ImplicitSplit: true,
+	EmptyAs:       &[]string{""}[0],
+}
+
 func (e apkEcosystem) Coarse(_ string) (string, error) {
+	// TODO(michaelkedar): semantic.AlpineVersion currently breaks transitivity rules
+	// (a < b, b < c, c < a) in some cases with invalid versions.
+	// Which makes coarse versions kinda broken.
 	return "", ErrCoarseNotSupported
 }