Make EmitCannotFindPackages testable and add tests

go/extractor/diagnostics/BUILD.bazel

@@ -1,6 +1,6 @@
 # generated running `bazel run //go/gazelle`, do not edit
 
-load("@rules_go//go:def.bzl", "go_library")
+load("@rules_go//go:def.bzl", "go_library", "go_test")
 
 go_library(
     name = "diagnostics",
@@ -9,3 +9,10 @@ go_library(
     visibility = ["//visibility:public"],
     deps = ["//go/extractor/util"],
 )
+
+go_test(
+    name = "diagnostics_test",
+    srcs = ["diagnostics_test.go"],
+    embed = [":diagnostics"],
+    deps = ["@com_github_stretchr_testify//assert"],
+)

go/extractor/diagnostics/diagnostics.go

@@ -169,7 +169,7 @@ func plural(n int, singular, plural string) string {
 
 const maxNumPkgPaths = 5
 
-func EmitCannotFindPackages(pkgPaths []string) {
+func EmitCannotFindPackages(writer DiagnosticsWriter, pkgPaths []string) {
 	numPkgPaths := len(pkgPaths)
 
 	numPrinted := numPkgPaths
@@ -216,7 +216,8 @@ func EmitCannotFindPackages(pkgPaths []string) {
 			"If any of the packages are already present in the repository, but were not found, then you may need a [custom build command](https://docs.github.com/en/code-security/how-tos/scan-code-for-vulnerabilities/manage-your-configuration/codeql-code-scanning-for-compiled-languages)."
 	}
 
-	emitDiagnostic(
+	emitDiagnosticTo(
+		writer,
 		"go/autobuilder/package-not-found",
 		"Some packages could not be found",
 		message,

go/extractor/diagnostics/diagnostics_test.go

@@ -0,0 +1,85 @@
+package diagnostics
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+type memoryDiagnosticsWriter struct {
+	diagnostics []diagnostic
+}
+
+func newMemoryDiagnosticsWriter() *memoryDiagnosticsWriter {
+	return &memoryDiagnosticsWriter{[]diagnostic{}}
+}
+
+func (writer *memoryDiagnosticsWriter) WriteDiagnostic(d diagnostic) {
+	writer.diagnostics = append(writer.diagnostics, d)
+}
+
+func Test_EmitCannotFindPackages_Default(t *testing.T) {
+	writer := newMemoryDiagnosticsWriter()
+
+	// Clear environment variables that affect the diagnostic message.
+	t.Setenv("GITHUB_EVENT_NAME", "")
+	t.Setenv("GITHUB_ACTIONS", "")
+
+	EmitCannotFindPackages(writer, []string{"github.com/github/foo"})
+
+	assert.Len(t, writer.diagnostics, 1, "Expected one diagnostic to be emitted")
+
+	d := writer.diagnostics[0]
+	assert.Equal(t, d.Source.Id, "go/autobuilder/package-not-found")
+	assert.Equal(t, d.Severity, string(severityWarning))
+	assert.True(t, d.Visibility.CliSummaryTable)
+	assert.True(t, d.Visibility.StatusPage)
+	assert.True(t, d.Visibility.Telemetry)
+	// Non-Actions suggestion for private registries
+	assert.Contains(t, d.MarkdownMessage, "ensure that the necessary credentials and environment variables are set up")
+	// Custom build command suggestion
+	assert.Contains(t, d.MarkdownMessage, "If any of the packages are already present in the repository")
+}
+
+func Test_EmitCannotFindPackages_Dynamic(t *testing.T) {
+	writer := newMemoryDiagnosticsWriter()
+
+	// Set environment variables that affect the diagnostic message.
+	t.Setenv("GITHUB_EVENT_NAME", "dynamic")
+	t.Setenv("GITHUB_ACTIONS", "true")
+
+	EmitCannotFindPackages(writer, []string{"github.com/github/foo"})
+
+	assert.Len(t, writer.diagnostics, 1, "Expected one diagnostic to be emitted")
+
+	d := writer.diagnostics[0]
+	assert.Equal(t, d.Source.Id, "go/autobuilder/package-not-found")
+	assert.Equal(t, d.Severity, string(severityWarning))
+	// Dynamic workflow suggestion for private registries
+	assert.Contains(t, d.MarkdownMessage, "can grant access to private registries for GitHub security products")
+	// No default suggestions for private registries and custom build command
+	assert.NotContains(t, d.MarkdownMessage, "ensure that the necessary credentials and environment variables are set up")
+	assert.NotContains(t, d.MarkdownMessage, "If any of the packages are already present in the repository")
+}
+
+func Test_EmitCannotFindPackages_Actions(t *testing.T) {
+	writer := newMemoryDiagnosticsWriter()
+
+	// Set environment variables that affect the diagnostic message.
+	t.Setenv("GITHUB_EVENT_NAME", "push")
+	t.Setenv("GITHUB_ACTIONS", "true")
+
+	EmitCannotFindPackages(writer, []string{"github.com/github/foo"})
+
+	assert.Len(t, writer.diagnostics, 1, "Expected one diagnostic to be emitted")
+
+	d := writer.diagnostics[0]
+	assert.Equal(t, d.Source.Id, "go/autobuilder/package-not-found")
+	assert.Equal(t, d.Severity, string(severityWarning))
+	// Advanced workflow suggestion for private registries
+	assert.Contains(t, d.MarkdownMessage, "add a step to your workflow which sets up")
+	// No default suggestion for private registries
+	assert.NotContains(t, d.MarkdownMessage, "ensure that the necessary credentials and environment variables are set up")
+	// Custom build command suggestion
+	assert.Contains(t, d.MarkdownMessage, "If any of the packages are already present in the repository")
+}

go/extractor/extractor.go

@@ -223,7 +223,7 @@ func ExtractWithFlags(buildFlags []string, patterns []string, extractTests bool,
 	})
 
 	if len(pkgsNotFound) > 0 {
-		diagnostics.EmitCannotFindPackages(pkgsNotFound)
+		diagnostics.EmitCannotFindPackages(diagnostics.DefaultWriter, pkgsNotFound)
 	}
 
 	for _, pkg := range pkgs {