platforms: add subarchless version of Only()

AkihiroSuda · AkihiroSuda · commit e22ce0fa0341 · 2021-01-15T14:58:14.000+09:00
`OnlyStrict()` returns a match comparer for a single platform.

Unlike `Only()`, `OnlyStrict()` does not match sub platforms.
So, "arm/vN" will not match "arm/vM" where M &lt; N, and "amd64" will not also match "386".

`OnlyStrict()` matches non-canonical forms. So, "arm64" matches "arm/64/v8".

Signed-off-by: Akihiro Suda &lt;akihiro.suda.cz@hco.ntt.co.jp&gt;
diff --git a/platforms/compare.go b/platforms/compare.go
@@ -85,6 +85,18 @@ func Only(platform specs.Platform) MatchComparer {
 	return Ordered(platformVector(Normalize(platform))...)
 }
 
+// OnlyStrict returns a match comparer for a single platform.
+//
+// Unlike Only, OnlyStrict does not match sub platforms.
+// So, "arm/vN" will not match "arm/vM" where M < N,
+// and "amd64" will not also match "386".
+//
+// OnlyStrict matches non-canonical forms.
+// So, "arm64" matches "arm/64/v8".
+func OnlyStrict(platform specs.Platform) MatchComparer {
+	return Ordered(Normalize(platform))
+}
+
 // Ordered returns a platform MatchComparer which matches any of the platforms
 // but orders them in order they are provided.
 func Ordered(platforms ...specs.Platform) MatchComparer {
diff --git a/platforms/compare_test.go b/platforms/compare_test.go
@@ -206,3 +206,190 @@ func TestOnly(t *testing.T) {
 		})
 	}
 }
+
+func TestOnlyStrict(t *testing.T) {
+	for _, tc := range []struct {
+		platform string
+		matches  map[bool][]string
+	}{
+		{
+			platform: "linux/amd64",
+			matches: map[bool][]string{
+				true: {
+					"linux/amd64",
+				},
+				false: {
+					"linux/386",
+					"linux/arm/v7",
+					"linux/arm64",
+					"windows/amd64",
+					"windows/arm",
+				},
+			},
+		},
+		{
+			platform: "linux/386",
+			matches: map[bool][]string{
+				true: {
+					"linux/386",
+				},
+				false: {
+					"linux/amd64",
+					"linux/arm/v7",
+					"linux/arm64",
+					"windows/amd64",
+					"windows/arm",
+				},
+			},
+		},
+		{
+			platform: "windows/amd64",
+			matches: map[bool][]string{
+				true: {"windows/amd64"},
+				false: {
+					"linux/amd64",
+					"linux/arm/v7",
+					"linux/arm64",
+					"windows/arm",
+				},
+			},
+		},
+		{
+			platform: "linux/arm/v8",
+			matches: map[bool][]string{
+				true: {
+					"linux/arm/v8",
+				},
+				false: {
+					"linux/arm",
+					"linux/arm/v5",
+					"linux/arm/v6",
+					"linux/arm/v7",
+					"linux/amd64",
+					"linux/arm/v4",
+					"linux/arm64",
+					"windows/amd64",
+					"windows/arm",
+				},
+			},
+		},
+		{
+			platform: "linux/arm/v7",
+			matches: map[bool][]string{
+				true: {
+					"linux/arm",
+					"linux/arm/v7",
+				},
+				false: {
+					"linux/arm/v5",
+					"linux/arm/v6",
+					"linux/amd64",
+					"linux/arm/v4",
+					"linux/arm/v8",
+					"linux/arm64",
+					"windows/amd64",
+					"windows/arm",
+				},
+			},
+		},
+		{
+			platform: "linux/arm/v6",
+			matches: map[bool][]string{
+				true: {
+					"linux/arm/v6",
+				},
+				false: {
+					"linux/arm/v5",
+					"linux/amd64",
+					"linux/arm",
+					"linux/arm/v4",
+					"linux/arm/v7",
+					"linux/arm/v8",
+					"linux/arm64",
+					"windows/amd64",
+					"windows/arm",
+				},
+			},
+		},
+		{
+			platform: "linux/arm/v5",
+			matches: map[bool][]string{
+				true: {
+					"linux/arm/v5",
+				},
+				false: {
+					"linux/amd64",
+					"linux/arm",
+					"linux/arm/v4",
+					"linux/arm/v6",
+					"linux/arm/v7",
+					"linux/arm/v8",
+					"linux/arm64",
+					"windows/amd64",
+					"windows/arm",
+				},
+			},
+		},
+		{
+			platform: "linux/arm/v4",
+			matches: map[bool][]string{
+				true: {
+					"linux/arm/v4",
+				},
+				false: {
+					"linux/amd64",
+					"linux/arm",
+					"linux/arm/v5",
+					"linux/arm/v6",
+					"linux/arm/v7",
+					"linux/arm/v8",
+					"linux/arm64",
+					"windows/amd64",
+					"windows/arm",
+				},
+			},
+		},
+		{
+			platform: "linux/arm64",
+			matches: map[bool][]string{
+				true: {
+					"linux/arm64",
+					"linux/arm64/v8",
+				},
+				false: {
+					"linux/arm",
+					"linux/arm/v5",
+					"linux/arm/v6",
+					"linux/arm/v7",
+					"linux/arm/v8",
+					"linux/amd64",
+					"linux/arm/v4",
+					"linux/arm/v9",
+					"linux/arm64/v9",
+					"windows/amd64",
+					"windows/arm",
+				},
+			},
+		},
+	} {
+		testcase := tc
+		t.Run(testcase.platform, func(t *testing.T) {
+			p, err := Parse(testcase.platform)
+			if err != nil {
+				t.Fatal(err)
+			}
+			m := OnlyStrict(p)
+			for shouldMatch, platforms := range testcase.matches {
+				for _, matchPlatform := range platforms {
+					mp, err := Parse(matchPlatform)
+					if err != nil {
+						t.Fatal(err)
+					}
+					if match := m.Match(mp); shouldMatch != match {
+						t.Errorf("OnlyStrict(%q).Match(%q) should return %v, but returns %v", testcase.platform, matchPlatform, shouldMatch, match)
+					}
+				}
+			}
+		})
+	}
+}
diff --git a/platforms/defaults.go b/platforms/defaults.go
@@ -36,3 +36,8 @@ func DefaultSpec() specs.Platform {
 		Variant: cpuVariant,
 	}
 }
+
+// DefaultStrict returns strict form of Default.
+func DefaultStrict() MatchComparer {
+	return OnlyStrict(DefaultSpec())
+}

Original file line number	Diff line number	Diff line change
`@@ -36,3 +36,8 @@ func DefaultSpec() specs.Platform {`
`36`	`36`	`Variant: cpuVariant,`
`37`	`37`	`}`
`38`	`38`	`}`
	`39`	`+`
	`40`	`+// DefaultStrict returns strict form of Default.`
	`41`	`+func DefaultStrict() MatchComparer {`
	`42`	`+ return OnlyStrict(DefaultSpec())`
	`43`	`+}`