From e9450e95eef63f44f881b411ef00fcbd3ad196d6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Philipp=20Kr=C3=BCger?= <philipp.krueger1@gmail.com>
Date: Mon, 13 Dec 2021 20:09:10 +0100
Subject: [PATCH] Remove toCapability & rename parse -> tryParsing

---
 src/attenuation.ts         |  5 ++---
 src/capability/wnfs.ts     | 25 ++-----------------------
 tests/emailCapabilities.ts |  9 +--------
 3 files changed, 5 insertions(+), 34 deletions(-)

diff --git a/src/attenuation.ts b/src/attenuation.ts
index a383821..fa4db83 100644
--- a/src/attenuation.ts
+++ b/src/attenuation.ts
@@ -5,8 +5,7 @@ import * as util from "./util"
 
 
 export interface CapabilitySemantics<A> {
-  parse(cap: Capability): A | null
-  toCapability(parsedCap: A): Capability
+  tryParsing(cap: Capability): A | null
   /**
    * This figures out whether a given `childCap` can be delegated from `parentCap`.
    * There are three possible results with three return types respectively:
@@ -51,7 +50,7 @@ export function capabilities<A>(
   function* findParsingCaps(ucan: Ucan<never>): Iterable<A & CapabilityInfo> {
     const capInfo = parseCapabilityInfo(ucan)
     for (const cap of ucan.payload.att) {
-      const parsedCap = capability.parse(cap)
+      const parsedCap = capability.tryParsing(cap)
       if (parsedCap != null) yield { ...parsedCap, ...capInfo }
     }
   }
diff --git a/src/capability/wnfs.ts b/src/capability/wnfs.ts
index 964d421..5714a45 100644
--- a/src/capability/wnfs.ts
+++ b/src/capability/wnfs.ts
@@ -41,7 +41,7 @@ export const wnfsPublicSemantics: CapabilitySemantics<WnfsPublicCapability> = {
    * }
    * ```
    */
-  parse(cap: Capability): WnfsPublicCapability | null {
+  tryParsing(cap: Capability): WnfsPublicCapability | null {
     if (typeof cap.wnfs !== "string" || !isWnfsCap(cap.cap)) return null
 
     // remove trailing slash
@@ -57,13 +57,6 @@ export const wnfsPublicSemantics: CapabilitySemantics<WnfsPublicCapability> = {
     }
   },
 
-  toCapability(parsed: WnfsPublicCapability): Capability {
-    return {
-      wnfs: `${parsed.user}/public/${parsed.publicPath.join("/")}`,
-      cap: parsed.cap,
-    }
-  },
-
   tryDelegating<T extends WnfsPublicCapability>(parentCap: T, childCap: T): T | null | CapabilityEscalation<WnfsPublicCapability> {
     // need to delegate the same user's file system
     if (childCap.user !== parentCap.user) return null
@@ -118,7 +111,7 @@ const wnfsPrivateSemantics: CapabilitySemantics<WnfsPrivateCapability> = {
    * }
    * ```
    */
-  parse(cap: Capability): WnfsPrivateCapability | null {
+  tryParsing(cap: Capability): WnfsPrivateCapability | null {
     if (typeof cap.wnfs !== "string" || !isWnfsCap(cap.cap)) return null
 
     // split up "boris.fission.name/private/fccXmZ8HYmpwxkvPSjwW9A" into "<user>/private/<inumberBase64url>"
@@ -135,20 +128,6 @@ const wnfsPrivateSemantics: CapabilitySemantics<WnfsPrivateCapability> = {
     }
   },
 
-  toCapability(parsed: WnfsPrivateCapability): Capability {
-    const inumbers = Array.from(parsed.requiredINumbers.values())
-    const [inumber] = inumbers
-    if (inumbers.length !== 1 || inumber == null) {
-      // Private wnfs capabilities will only have an encoding with a single inumber.
-      // Multiple inumbers are the result of delegations with multiple private capabilities interacting.
-      throw new Error(`Can only construct a private capability with exactly one inumber.`)
-    }
-    return {
-      wnfs: `${parsed.user}/private/${inumber}`,
-      cap: parsed.cap,
-    }
-  },
-
   tryDelegating<T extends WnfsPrivateCapability>(parentCap: T, childCap: T): T | null | CapabilityEscalation<WnfsPrivateCapability> {
     // If the users don't match, these capabilities are unrelated.
     if (childCap.user !== parentCap.user) return null
diff --git a/tests/emailCapabilities.ts b/tests/emailCapabilities.ts
index 910ff4c..087bbdb 100644
--- a/tests/emailCapabilities.ts
+++ b/tests/emailCapabilities.ts
@@ -11,7 +11,7 @@ export interface EmailCapability {
 
 export const emailSemantics: CapabilitySemantics<EmailCapability> = {
 
-  parse(cap: Capability): EmailCapability | null {
+  tryParsing(cap: Capability): EmailCapability | null {
     if (typeof cap.email === "string" && cap.cap === "SEND") {
       return {
         email: cap.email,
@@ -21,13 +21,6 @@ export const emailSemantics: CapabilitySemantics<EmailCapability> = {
     return null
   },
 
-  toCapability(parsed: EmailCapability): Capability {
-    return {
-      email: parsed.email,
-      cap: parsed.cap,
-    }
-  },
-
   tryDelegating<T extends EmailCapability>(parentCap: T, childCap: T): T | null | CapabilityEscalation<EmailCapability> {
     // potency is always "SEND" anyway, so doesn't need to be checked
     return childCap.email === parentCap.email ? childCap : null