feat(core): add token expiration helpers

lib/core/utilities.js

@@ -1,3 +1,5 @@
+import jwtDecode, { InvalidTokenError } from 'jwt-decode'
+
 export const isUnset = o => typeof o === 'undefined' || o === null
 export const isSet = o => !isUnset(o)
 
@@ -110,3 +112,67 @@ export function getProp (holder, propName) {
 
   return result
 }
+
+const TokenExpirationStatusEnum = Object.freeze({
+  UNKNOWN: 'UNKNOWN',
+  VALID: 'VALID',
+  EXPIRED: 'EXPIRED',
+  REFRESH_EXPIRED: 'REFRESH_EXPIRED'
+})
+
+export class TokenExpirationStatus {
+  constructor (scheme) {
+    this.token = scheme.$auth.getToken(scheme.name)
+    this.refreshToken = scheme.$auth.getRefreshToken(scheme.name)
+
+    this.status = this._calculateTokenStatus()
+  }
+
+  _calculateTokenStatus () {
+    const now = Date.now()
+    let tokenExpiresAt, refreshTokenExpiresAt
+
+    try {
+      tokenExpiresAt = jwtDecode(this.token).exp * 1000
+      refreshTokenExpiresAt = jwtDecode(this.refreshToken).exp * 1000
+    } catch (error) {
+      // If the token is not jwt, we can't decode and refresh it
+      if (error instanceof InvalidTokenError) {
+        return TokenExpirationStatusEnum.UNKNOWN
+      }
+      throw error
+    }
+
+    // Give us some slack to help the token from expiring between validation and usage
+    const timeSlackMillis = 500
+    tokenExpiresAt -= timeSlackMillis
+    refreshTokenExpiresAt -= timeSlackMillis
+
+    // Token is still valid
+    if (now < tokenExpiresAt) {
+      return TokenExpirationStatusEnum.VALID
+    }
+
+    if (now > refreshTokenExpiresAt) {
+      return TokenExpirationStatusEnum.REFRESH_EXPIRED
+    }
+
+    return TokenExpirationStatusEnum.EXPIRED
+  }
+
+  unknown () {
+    return TokenExpirationStatusEnum.UNKNOWN === this.status
+  }
+
+  valid () {
+    return TokenExpirationStatusEnum.VALID === this.status
+  }
+
+  expired () {
+    return TokenExpirationStatusEnum.EXPIRED === this.status
+  }
+
+  refreshExpired () {
+    return TokenExpirationStatusEnum.REFRESH_EXPIRED === this.status
+  }
+}

package.json

@@ -47,6 +47,7 @@
     "cookie": "^0.4.0",
     "is-https": "^1.0.0",
     "js-cookie": "^2.2.1",
+    "jwt-decode": "^2.2.0",
     "lodash": "^4.17.15",
     "nanoid": "^2.1.11"
   },