Add Metadata 2.5/2.6 support, fix License-File multiplicity

CHANGELOG.md

@@ -9,6 +9,17 @@ mistaken for a safe patch upgrade.
 
 ## [Unreleased]
 
+### Added
+
+- `distribution`: Metadata 2.5 (PEP 794) and 2.6 (PEP 808) are now recognized.
+  Metadata 2.5 adds `Import-Name` and `Import-Namespace` fields; 2.6 has no new
+  fields (behavior change for `Dynamic` only).
+
+### Fixed
+
+- `distribution`: `License-File` is now parsed as a multi-value field, matching
+  the PEP 639 spec. Previously it was incorrectly treated as single-value.
+
 ## [0.11.0] - 2026-09-25
 
 ### Breaking

distribution/internal/distributions/distribution.go

@@ -141,9 +141,16 @@ var HeaderAttrs2_3 = HeaderAttrs2_2 // PEP 685
 
 var HeaderAttrs2_4 = append(HeaderAttrs2_3, []HeaderAttr{ // PEP 639
 	{"License-Expression", "license_expression", false},
-	{"License-File", "license_file", false},
+	{"License-File", "license_files", true},
 }...)
 
+var HeaderAttrs2_5 = append(HeaderAttrs2_4, []HeaderAttr{ // PEP 794
+	{"Import-Name", "import_names", true},
+	{"Import-Namespace", "import_namespaces", true},
+}...)
+
+var HeaderAttrs2_6 = HeaderAttrs2_5 // PEP 808 (no new fields, behavior change for Dynamic)
+
 var HeaderAttrs = map[string][]HeaderAttr{
 	"1.0": HeaderAttrs1_0,
 	"1.1": HeaderAttrs1_1,
@@ -153,6 +160,8 @@ var HeaderAttrs = map[string][]HeaderAttr{
 	"2.2": HeaderAttrs2_2,
 	"2.3": HeaderAttrs2_3,
 	"2.4": HeaderAttrs2_4,
+	"2.5": HeaderAttrs2_5,
+	"2.6": HeaderAttrs2_6,
 }
 
 type Distribution interface {
@@ -205,8 +214,11 @@ type BaseDistribution struct {
 	// version 2.2
 	Dynamic []string `json:"dynamic"`
 	// version 2.4
-	LicenseExpression string `json:"license_expression"`
-	LicenseFile       string `json:"license_file"`
+	LicenseExpression string   `json:"license_expression"`
+	LicenseFiles      []string `json:"license_files"`
+	// version 2.5
+	ImportNames      []string `json:"import_names"`
+	ImportNamespaces []string `json:"import_namespaces"`
 }
 
 func (bd *BaseDistribution) GetHeaderAttrs() ([]HeaderAttr, error) {

distribution/parse_fixture_test.go

@@ -168,7 +168,7 @@ func TestParse_WheelMultiValueFields(t *testing.T) {
 		"provides_extra":     {"extra-one", "extra-two"},
 		"project_urls":       {"Homepage, https://example.invalid/gppfixture-alpha", "Source, https://example.invalid/gppfixture-alpha/src"},
 		"license_expression": {"MIT"},
-		"license_file":       {"LICENSE.txt"},
+		"license_files":      {"LICENSE.txt"},
 		"dynamic":            {"requires-dist", "license-file"},
 		"description":        {body},
 		"filetype":           {"bdist_wheel"},
@@ -397,3 +397,56 @@ func TestParse_DirectoryExpansionWheelFirst(t *testing.T) {
 	require.NotEqual(t, -1, sdistIdx, "sdist not found in results")
 	assert.Less(t, wheelIdx, sdistIdx, "every wheel must come before every sdist")
 }
+
+// TestParse_WheelMetadata25 verifies parsing of Metadata-Version 2.5 (PEP 794)
+// with Import-Name and Import-Namespace fields.
+func TestParse_WheelMetadata25(t *testing.T) {
+	dir := t.TempDir()
+	wheelPath := filepath.Join(dir, "gppfixture_eta-1.0.0-py3-none-any.whl")
+
+	header := strings.Join([]string{
+		"Metadata-Version: 2.5",
+		"Name: gppfixture-eta",
+		"Version: 1.0.0",
+		"Import-Name: gppfixture_eta",
+		"Import-Name: gppfixture_eta.submodule",
+		"Import-Namespace: gppfixture_shared",
+	}, "\n")
+	body := "Fixture eta description.\n"
+	metadata := header + "\n\n" + body
+
+	writeWheelFixture(t, wheelPath, []fixtureEntry{
+		{name: "gppfixture_eta-1.0.0.dist-info/METADATA", contents: metadata},
+		{name: "gppfixture_eta-1.0.0.dist-info/WHEEL", contents: "Wheel-Version: 1.0\nGenerator: test\nRoot-Is-Purelib: true\nTag: py3-none-any\n"},
+		{name: "gppfixture_eta-1.0.0.dist-info/RECORD", contents: ""},
+	})
+
+	sha2, blake2 := fileDigests(t, wheelPath)
+
+	packages, err := distribution.Parse(wheelPath)
+	require.NoError(t, err)
+	require.Len(t, packages, 1)
+	pkg := packages[0]
+
+	assert.Equal(t, "gppfixture_eta-1.0.0-py3-none-any.whl", pkg.BaseFilename)
+	assert.Equal(t, sha2, pkg.SHA2Digest)
+	assert.Equal(t, blake2, pkg.Blake2_256Digest)
+
+	got := pkg.MetadataMap()
+
+	want := map[string][]string{
+		":action":           {"file_upload"},
+		"protocol_version":  {"1"},
+		"name":              {"gppfixture-eta"},
+		"metadata_version":  {"2.5"},
+		"version":           {"1.0.0"},
+		"import_names":      {"gppfixture_eta", "gppfixture_eta.submodule"},
+		"import_namespaces": {"gppfixture_shared"},
+		"description":       {body},
+		"filetype":          {"bdist_wheel"},
+		"pyversion":         {"py3"},
+		"sha256_digest":     {sha2},
+		"blake2_256_digest": {blake2},
+	}
+	assert.Equal(t, want, got)
+}