internal/relui: display parameters, even if their type isn't string

Some parameters have a type other than string, so unmarshaling them into
a map with string value type would fail. Prefer to make such problems
visible by returning any non-nil errors from workflowParams to caller.

For now, display parameter values in their JSON form, since it's simple,
quite human readable, and has a nice side-effect of turning any leading
or trailing spaces apparent. (In the future we can consider investing
into a more elaborate parameter layout, as needed.)

Fixes golang/go#54240.

Change-Id: I2a6048e5b5b0d42257b6088c8ba01b26216a3c39
Reviewed-on: https://go-review.googlesource.com/c/build/+/422554
Reviewed-by: Jenny Rakoczy <[email protected]>
Reviewed-by: Dmitri Shuralyov <[email protected]>
Run-TryBot: Dmitri Shuralyov <[email protected]>
Auto-Submit: Dmitri Shuralyov <[email protected]>
TryBot-Result: Gopher Robot <[email protected]>

Author: dmitshur

internal/relui/web.go

@@ -144,10 +144,17 @@ type homeResponse struct {
 	InactiveWorkflows []db.Workflow
 }
 
-func workflowParams(wf db.Workflow) map[string]string {
-	params := make(map[string]string)
-	json.Unmarshal([]byte(wf.Params.String), &params)
-	return params
+func workflowParams(wf db.Workflow) (map[string]string, error) {
+	rawParams := make(map[string]json.RawMessage)
+	err := json.Unmarshal([]byte(wf.Params.String), &rawParams)
+	if err != nil {
+		return nil, err
+	}
+	params := make(map[string]string, len(rawParams))
+	for p, v := range rawParams {
+		params[p] = string(v)
+	}
+	return params, nil
 }
 
 // homeHandler renders the homepage.

internal/relui/web_test.go

@@ -871,3 +871,17 @@ func TestResultDetail(t *testing.T) {
 	}
 
 }
+
+func TestWorkflowParams(t *testing.T) {
+	got, err := workflowParams(db.Workflow{Params: nullString(`{"greeting": "hello", "names": ["alice", "bob"]}`)})
+	if err != nil {
+		t.Fatalf("workflowParams: err = %v, wanted no error", err)
+	}
+	want := map[string]string{
+		"greeting": `"hello"`,
+		"names":    `["alice", "bob"]`,
+	}
+	if diff := cmp.Diff(want, got); diff != "" {
+		t.Errorf("workflowParams mismatch (-want +got):\n%s", diff)
+	}
+}