type (
		testHeader struct { // WriteHeader(hdr) == wantErr
			hdr     Header
			wantErr error
		}
		testWrite struct { // Write(str) == (wantCnt, wantErr)
			str     string
			wantCnt int
			wantErr error
		}
		testReadFrom struct { // ReadFrom(testFile{ops}) == (wantCnt, wantErr)
			ops     fileOps
			wantCnt int64
			wantErr error
		}
		testClose struct { // Close() == wantErr
			wantErr error
		}

		fv      formValues
		expired bool
		wantErr string
	}

	// Test case just contains fields we override from defaultFormVals.
	testCases := []testCase{
		{
			name:    "happy path no errors",
			fv:      defaultFormVals.Clone(),
			wantErr: "",
		},
		{
			name:    "expired policy document",
			fv:      defaultFormVals.Clone(),
			expired: true,
			wantErr: "Invalid according to Policy: Policy expired",

}

func TestFileReader(t *testing.T) {
	type (
		testRead struct { // Read(cnt) == (wantStr, wantErr)
			cnt     int
			wantStr string
			wantErr error
		}
		testWriteTo struct { // WriteTo(testFile{ops}) == (wantCnt, wantErr)
			ops     fileOps
			wantCnt int64
			wantErr error
		}
		testRemaining struct { // logicalRemaining() == wantLCnt, physicalRemaining() == wantPCnt

	}
	for _, tt := range tests {
		got, err := parseHexUint([]byte(tt.in))
		if tt.wantErr != "" {
			if err != nil && !strings.Contains(err.Error(), tt.wantErr) {
				t.Errorf("parseHexUint(%q) = %v, %v; want error %q", tt.in, got, err, tt.wantErr)
			}
		} else {
			if err != nil || got != tt.want {
				t.Errorf("parseHexUint(%q) = %v, %v; want %v", tt.in, got, err, tt.want)
			}

			br := NewReaderSize(r, size)
			want := func(s string, wantErr error) {
				p := make([]byte, 50)
				n, err := br.Read(p)
				if err != wantErr || n != len(s) || string(p[:n]) != s {
					t.Fatalf("read(%d) = %q, %v, want %q, %v", len(p), string(p[:n]), err, s, wantErr)
				}
				t.Logf("read(%d) = %q, %v", len(p), string(p[:n]), err)
			}
			want("abc", nil)

				if err != nil {
					if !test.wantErr {
						t.Errorf("%s: %v", path, err)
					}
					sawErr = true
					return nil
				}
				files = append(files, path)
				return nil
			})
			if err != nil {
				t.Errorf("fs.WalkDir error: %v", err)
			}
			if test.wantErr && !sawErr {
				t.Error("succeeded but want error")
			} else if !test.wantErr && sawErr {
				t.Error("unexpected error")

			}
			var apiErr APIErrorResponse
			err = xml.Unmarshal(b, &apiErr)
			if err != nil {
				t.Fatal(err)
			}
			gotErr := apiErr.Code
			wantErr := testCase.wantAPICode
			if gotErr != wantErr {
				t.Errorf("test %d: want api error %q, got %q", i, wantErr, gotErr)
			}
			if testCase.wantHeaders != nil {
				for k, v := range testCase.wantHeaders {
					got := rec.Header().Get(k)
					if got != v {