🏗 Updated "slack" setting into "slack_{url,username}"

refs https://github.com/TryGhost/Ghost/issues/10318

- Object format used in previous "slack" setting was considered an
anti-pattern. Flag structure of separate slack_url and slack_username
values was extracted out of the "slack" JSON.

core/server/data/migrations/versions/4.0/09-refactor-slack-setting.js

@@ -0,0 +1,64 @@
+const ObjectId = require('bson-objectid').default;
+const {createIrreversibleMigration} = require('../../utils');
+
+module.exports = createIrreversibleMigration(async (knex) => {
+    const slackSetting = await knex('settings')
+        .select('value')
+        .where({
+            key: 'slack'
+        })
+        .first();
+
+    let slackUrl = '';
+    let slackUsername = '';
+    try {
+        // example value that used to be stored in here:
+        // value: [{
+        //     "url":"https://hooks.slack.com/services/TC_REDACTED/B01_REDACTED/mk_REDACTED",
+        //     "username":"Ghost"
+        // }]
+        const value = JSON.parse(slackSetting.value)[0];
+
+        slackUrl = value.url;
+        slackUsername = value.username;
+    } catch (err) {
+        slackUrl = '';
+        slackUsername = 'Ghost';
+    }
+
+    const now = knex.raw('CURRENT_TIMESTAMP');
+
+    await knex('settings')
+        .insert({
+            id: ObjectId.generate(),
+            key: 'slack_url',
+            group: 'slack',
+            type: 'string',
+            flags: null,
+            value: slackUrl,
+            created_by: 1,
+            created_at: now,
+            updated_by: 1,
+            updated_at: now
+        });
+
+    await knex('settings')
+        .insert({
+            id: ObjectId.generate(),
+            key: 'slack_username',
+            group: 'slack',
+            type: 'string',
+            flags: null,
+            value: slackUsername,
+            created_by: 1,
+            created_at: now,
+            updated_by: 1,
+            updated_at: now
+        });
+
+    await knex('settings')
+        .where({
+            key: 'slack'
+        })
+        .del();
+});

core/server/data/schema/default-settings.json

@@ -401,9 +401,13 @@
         }
     },
     "slack": {
-        "slack": {
-            "defaultValue": "[{\"url\":\"\", \"username\":\"Ghost\"}]",
-            "type": "array"
+        "slack_url": {
+            "defaultValue": "",
+            "type": "string"
+        },
+        "slack_username": {
+            "defaultValue": "Ghost",
+            "type": "string"
         }
     },
     "unsplash": {

test/unit/data/schema/integrity_spec.js

@@ -34,7 +34,7 @@ describe('DB version integrity', function () {
     // Only these variables should need updating
     const currentSchemaHash = '3f88f2c34001cc34d74d945dbf4f0bb5';
     const currentFixturesHash = '370d0da0ab7c45050b2ff30bce8896ba';
-    const currentSettingsHash = '162f9294cc427eb32bc0577006c385ce';
+    const currentSettingsHash = '24453dc02be9df7284acf1748862a545';
     const currentRoutesHash = '3d180d52c663d173a6be791ef411ed01';
 
     // If this test is failing, then it is likely a change has been made that requires a DB version bump,