From e7b9f990b6084e22f3905ee9999c18bd19f04d49 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pedro=20Guti=C3=A9rrez?= <pedrogp9693@gmail.com>
Date: Mon, 11 Mar 2019 22:46:27 +0100
Subject: [PATCH] Add conversion helpers for `did:op:` prefixes.

---
 src/utils/ConversionTypeHelpers.ts       | 38 +++++++++++++++++++-----
 test/utils/ConversionTypeHelpers.test.ts | 37 +++++++++++++++++++++--
 2 files changed, 64 insertions(+), 11 deletions(-)

diff --git a/src/utils/ConversionTypeHelpers.ts b/src/utils/ConversionTypeHelpers.ts
index ee71225..50cee05 100644
--- a/src/utils/ConversionTypeHelpers.ts
+++ b/src/utils/ConversionTypeHelpers.ts
@@ -1,13 +1,35 @@
 import { Logger } from './Logger'
 
+// Ox transformer
 export const zeroX = (input: string) => zeroXTransformer(input, true)
 export const noZeroX = (input: string) => zeroXTransformer(input, false)
-
-export function zeroXTransformer(input: string, zeroOutput: boolean) {
-    const match = input.match(/^(?:0x)?([a-f0-9]+)$/i)
-    if (!match) {
-        Logger.warn(`Input transformation failed.`)
-        return input
-    }
-    return (zeroOutput ? "0x" : "") + match[1]
+export function zeroXTransformer(input: string = "", zeroOutput: boolean) {
+    const {valid, output} = inputMatch(input, /^(?:0x)*([a-f0-9]+)$/i, "zeroXTransformer")
+    return (zeroOutput && valid ? "0x" : "") + output
+}
+
+// did:op: transformer
+export const didPrefixed = (input: string) => didTransformer(input, true)
+export const noDidPrefixed = (input: string) => didTransformer(input, false)
+export function didTransformer(input: string = "", prefixOutput: boolean) {
+    const {valid, output} = inputMatch(input, /^(?:0x|did:op:)*([a-f0-9]{64})$/i, "didTransformer")
+    return (prefixOutput && valid ? "did:op:" : "") + output
+}
+
+// 0x + did:op: transformer
+export const didZeroX = (input: string) => zeroX(didTransformer(input, false))
+
+// Shared functions
+function inputMatch(input: string, regexp: RegExp, conversorName: string): {valid: boolean, output: string} {
+        if (typeof input !== "string") {
+        Logger.debug("Not input string:")
+        Logger.debug(input)
+        throw new Error(`[${conversorName}] Expected string, input type: ${typeof input}`);
+    }
+    const match = input.match(regexp)
+    if (!match) {
+        Logger.warn(`[${conversorName}] Input transformation failed.`)
+        return {valid: false, output: input}
+    }
+    return {valid: true, output: match[1]}
 }
diff --git a/test/utils/ConversionTypeHelpers.test.ts b/test/utils/ConversionTypeHelpers.test.ts
index 143ee76..33ab47e 100644
--- a/test/utils/ConversionTypeHelpers.test.ts
+++ b/test/utils/ConversionTypeHelpers.test.ts
@@ -1,8 +1,8 @@
 import { assert } from "chai"
-import { zeroX, noZeroX } from "../../src/utils/ConversionTypeHelpers"
+import { zeroX, noZeroX, didPrefixed, noDidPrefixed } from "../../src/utils/ConversionTypeHelpers"
 
-describe("ConversionTypeHelpers", () => {
-    describe("#zeroX()", () => {
+describe.only("ConversionTypeHelpers", () => {
+    describe("#zeroXTransformer()", () => {
         it("should return the input if it's not hex value", async () => {
             const result1 = zeroX("Test 1")
             const result2 = noZeroX("Test 2")
@@ -24,4 +24,35 @@ describe("ConversionTypeHelpers", () => {
             assert.equal(result2, "1234")
         })
     })
+
+    describe("#didTransformer()", () => {
+        const did = "a".repeat(64)
+
+        it("should return the input if it's not valid", async () => {
+            const result1 = didPrefixed("Test 1")
+            const result2 = noDidPrefixed("Test 2")
+            const result3 = noDidPrefixed("Test 3")
+            assert.equal(result1, "Test 1")
+            assert.equal(result2, "Test 2")
+            assert.equal(result3, "Test 3")
+        })
+
+        it("should return the value with did:op: prefix", async () => {
+            const result1 = didPrefixed(`0x${did}`)
+            const result2 = didPrefixed(did)
+            const result3 = didPrefixed(`did:op:${did}`)
+            assert.equal(result1, `did:op:${did}`)
+            assert.equal(result2, `did:op:${did}`)
+            assert.equal(result3, `did:op:${did}`)
+        })
+
+        it("should return the value without did:op: prefix", async () => {
+            const result1 = noDidPrefixed(`0x${did}`)
+            const result2 = noDidPrefixed(did)
+            const result3 = noDidPrefixed(`did:op:${did}`)
+            assert.equal(result1, did)
+            assert.equal(result2, did)
+            assert.equal(result3, did)
+        })
+    })
 })