[milo] Add BuildSummary and common models.

milo/appengine/common/model/status.go

+// Copyright 2017 The LUCI Authors. All rights reserved.
+// Use of this source code is governed under the Apache License, Version 2.0
+// that can be found in the LICENSE file.
+
+//go:generate stringer -type=Status
+
+package model
+
+import "encoding/json"
+
+// Status is a discrete status for the purpose of colorizing a component.
+// These are based off the Material Design Bootstrap color palettes.
+type Status int
+
+const (
+        // NotRun if the component has not yet been run.
+        NotRun Status = iota // 100 Gray
+
+        // Running if the component is currently running.
+        Running // 100 Teal
+
+        // Success if the component has finished executing and is not noteworthy.
+        Success // A200 Green
+
+        // Failure if the component has finished executing and contains a failure.
+        Failure // A200 Red
+
+        // Warning just like from the buildbot days.
+        Warning // 200 Yellow
+
+        // InfraFailure if the component has finished incompletely due to a failure in infra.
+        InfraFailure // A100 Purple
+
+        // Exception if the component has finished incompletely and unexpectedly. This
+        // is used for buildbot builds.
+        Exception // A100 Purple
+
+        // Expired if the component was never scheduled due to resource exhaustion.
+        Expired // A200 Purple
+
+        // DependencyFailure if the component has finished incompletely due to a failure in a
+        // dependency.
+        DependencyFailure // 100 Amber
+
+        // WaitingDependency if the component has finished or paused execution due to an
+        // incomplete dep.
+        WaitingDependency // 100 Brown
+)
+
+// Terminal returns true if the step status won't change.
+func (s Status) Terminal() bool {
+        switch s {
+        case Success, Failure, InfraFailure, Warning, DependencyFailure, Expired:
+                return true
+        default:
+                return false
+        }
+}
+
+// MarshalJSON renders enums into String rather than an int when marshalling.
+func (s Status) MarshalJSON() ([]byte, error) {
+        return json.Marshal(s.String())
+}