test: add regression test for I18nString filter

The AQL fragment created by this filter generates an internal error in ArangoDB 3.12.0 due to a regression.

The bug will be fixed with ArangoDB 3.12.1.

.vscode/settings.json

@@ -0,0 +1,3 @@
+{
+  "typescript.tsdk": "node_modules/typescript/lib"
+}

spec/regression/logistics/model/country.graphqls

@@ -3,6 +3,7 @@ type Country
     @roles(read: ["allusers"], readWrite: ["admin"]) {
     isoCode: String @key
     description: [Translation]
+    descriptionI18nString: I18nString
     totalInvestment: String @roles(readWrite: "accounting")
     someKey: String @flexSearch
 }

spec/regression/logistics/test-data.json

@@ -15,6 +15,10 @@
             "translation": "Germany"
           }
         ],
+        "descriptionI18nString": {
+          "de": "Deutschland",
+          "en": "Germany"
+        },
         "totalInvestment": "EUR 50000000",
         "someKey": "1"
       },
@@ -31,6 +35,10 @@
             "translation": "United Kingdom"
           }
         ],
+        "descriptionI18nString": {
+          "de": "Vereinigtes Königreich",
+          "en": "United Kingdom"
+        },
         "totalInvestment": "EUR 3000000",
         "someKey": "2"
       },
@@ -47,6 +55,10 @@
             "translation": "United States"
           }
         ],
+        "descriptionI18nString": {
+          "de": "Vereinigte Staaten",
+          "en": "United States"
+        },
         "someKey": null
       },
       {

spec/regression/logistics/tests/filter-stringmap-in-root-entities.graphql

@@ -0,0 +1,17 @@
+query filterI18nString {
+    allCountries(filter: { descriptionI18nString_some: { value: "Germany" } }) {
+        isoCode
+    }
+}
+
+query filterI18nStringWithCorrectLanguage {
+    allCountries(filter: { descriptionI18nString_some: { language: "en", value: "Germany" } }) {
+        isoCode
+    }
+}
+
+query filterI18nStringWithIncorrectLanguage {
+    allCountries(filter: { descriptionI18nString_some: { language: "de", value: "Germany" } }) {
+        isoCode
+    }
+}

spec/regression/logistics/tests/filter-stringmap-in-root-entities.result.json

@@ -0,0 +1,25 @@
+{
+  "filterI18nString": {
+    "data": {
+      "allCountries": [
+        {
+          "isoCode": "DE"
+        }
+      ]
+    }
+  },
+  "filterI18nStringWithCorrectLanguage": {
+    "data": {
+      "allCountries": [
+        {
+          "isoCode": "DE"
+        }
+      ]
+    }
+  },
+  "filterI18nStringWithIncorrectLanguage": {
+    "data": {
+      "allCountries": []
+    }
+  }
+}