Changes to cache_test.go. All files

cache_test.go

new file mode 100644@@ -0,0 +1,72 @@+package main++import (+	"context"+	"os"+	"path/filepath"+	"testing"+)++// The cache drops the least recently used value past its budget, and a+// budget of 0 keeps nothing.+func TestCacheBudget(t *testing.T) {+	c := newCache(25) // two of the 10-byte entries, keys included+	c.put("a", 1, 9)+	c.put("b", 2, 9)+	c.get("a")+	c.put("c", 3, 9)+	if _, ok := c.get("b"); ok {+		t.Error("b, the least recently used, was kept")+	}+	for _, k := range []string{"a", "c"} {+		if _, ok := c.get(k); !ok {+			t.Errorf("%s was dropped", k)+		}+	}+	none := newCache(0)+	none.put("a", 1, 0)+	if _, ok := none.get("a"); ok {+		t.Error("a budget of 0 kept a value")+	}+}++func TestParseSize(t *testing.T) {+	for s, want := range map[string]int64{"0": 0, "512": 512, "64K": 64 << 10, "32M": 32 << 20, "1g": 1 << 30} {+		if got, err := parseSize(s); err != nil || got != want {+			t.Errorf("%s: %d %v, want %d", s, got, err, want)+		}+	}+	for _, s := range []string{"", "M", "lots", "-1", "1T"} {+		if _, err := parseSize(s); err == nil {+			t.Errorf("%q: no error", s)+		}+	}+}++// HEAD read from the repo's files follows each commit, so a cached+// history never outlives it; a repo made in a directory that had none is+// found.+func TestCachedHeadFollowsCommits(t *testing.T) {+	needGit(t)+	s, dir := repoTree(t)+	tr := s.list()[0]+	ctx := context.Background()+	_, first := tr.gitHead("index.md")+	before := tr.lastCommit(ctx, "index.md")+	os.WriteFile(filepath.Join(dir, "index.md"), []byte("# Changed\n"), 0o644)+	commitAll(t, dir, "Change the index")+	_, second := tr.gitHead("index.md")+	after := tr.lastCommit(ctx, "index.md")+	if first == second || before == nil || after == nil || after.subject != "Change the index" {+		t.Errorf("HEAD %q then %q; last commit %v then %v", first, second, before, after)+	}++	plain := t.TempDir()+	if r := repoAt(ctx, plain); r.complaint == "" {+		t.Fatalf("%s is in a repo: %+v", plain, r)+	}+	git(ctx, plain, "init", "-q")+	if r := repoAt(ctx, plain); r.complaint != "" {+		t.Errorf("new repo not found: %s", r.complaint)+	}+}