Logs: Do not insert log-line into log-fields in json download (#70901)

* logs: do not insert log-line into log-fields in json download

* fixed test after merge

public/app/features/logs/components/logParser.test.ts

@@ -12,6 +12,7 @@ describe('logParser', () => {
         dataFrame: new MutableDataFrame({
           refId: 'A',
           fields: [
+            testLineField,
             testStringField,
             {
               name: 'labels',
@@ -34,6 +35,7 @@ describe('logParser', () => {
         dataFrame: new MutableDataFrame({
           refId: 'A',
           fields: [
+            testLineField,
             testStringField,
             {
               name: 'labels',
@@ -55,6 +57,7 @@ describe('logParser', () => {
         dataFrame: new MutableDataFrame({
           refId: 'A',
           fields: [
+            testLineField,
             testStringField,
             {
               name: 'labels',
@@ -83,6 +86,7 @@ describe('logParser', () => {
         dataFrame: new MutableDataFrame({
           refId: 'A',
           fields: [
+            testLineField,
             testStringField,
             {
               name: 'id',
@@ -138,7 +142,7 @@ describe('logParser', () => {
         entryFieldIndex: 10,
         dataFrame: new MutableDataFrame({
           refId: 'A',
-          fields: [{ ...testStringField }],
+          fields: [testLineField, { ...testStringField }],
         }),
       });
 
@@ -210,6 +214,13 @@ describe('logParser', () => {
   });
 });
 
+const testLineField = {
+  name: 'body',
+  type: FieldType.string,
+  config: {},
+  values: ['line1'],
+};
+
 const testStringField = {
   name: 'test_field_string',
   type: FieldType.string,

public/app/features/logs/components/logParser.ts

@@ -86,9 +86,26 @@ export const getDataframeFields = memoizeOne(
 );
 
 function shouldRemoveField(field: Field, index: number, row: LogRowModel) {
+  // hidden field, remove
+  if (field.config.custom?.hidden) {
+    return true;
+  }
+
+  // field with data-links, keep
+  if ((field.config.links ?? []).length > 0) {
+    return false;
+  }
+
+  // field that has empty value (we want to keep 0 or empty string)
+  if (field.values[row.rowIndex] == null) {
+    return true;
+  }
+
+  // the remaining checks use knowledge of how we parse logs-dataframes
+
   // Remove field if it is:
   // "labels" field that is in Loki used to store all labels
-  if (field.name === 'labels' && field.type === FieldType.other && (field.config.links?.length || 0) === 0) {
+  if (field.name === 'labels' && field.type === FieldType.other) {
     return true;
   }
   // id and tsNs are arbitrary added fields in the backend and should be hidden in the UI
@@ -103,13 +120,12 @@ function shouldRemoveField(field: Field, index: number, row: LogRowModel) {
   ) {
     return true;
   }
-  // hidden field
-  if (field.config.custom?.hidden) {
-    return true;
-  }
-  // field that has empty value (we want to keep 0 or empty string)
-  if (field.values[row.rowIndex] == null) {
+
+  // first string-field is the log-line
+  const firstStringFieldIndex = row.dataFrame.fields.findIndex((f) => f.type === FieldType.string);
+  if (firstStringFieldIndex === index) {
     return true;
   }
+
   return false;
 }

public/app/features/logs/utils.test.ts

@@ -221,9 +221,19 @@ describe('checkLogsError()', () => {
 
 describe('logRowsToReadableJson', () => {
   const testRow: LogRowModel = {
-    rowIndex: 1,
+    rowIndex: 0,
     entryFieldIndex: 0,
-    dataFrame: new MutableDataFrame(),
+    dataFrame: {
+      length: 1,
+      fields: [
+        {
+          name: 'body',
+          type: FieldType.string,
+          config: {},
+          values: ['test entry'],
+        },
+      ],
+    },
     entry: 'test entry',
     hasAnsi: false,
     hasUnescapedContent: false,
@@ -239,8 +249,23 @@ describe('logRowsToReadableJson', () => {
     timeUtc: '',
     uid: '2',
   };
-  const testDf = new MutableDataFrame();
-  testDf.addField({ name: 'foo2', values: ['bar2'] });
+  const testDf: DataFrame = {
+    length: 1,
+    fields: [
+      {
+        name: 'body',
+        type: FieldType.string,
+        config: {},
+        values: ['test entry'],
+      },
+      {
+        name: 'foo2',
+        type: FieldType.string,
+        config: {},
+        values: ['bar2'],
+      },
+    ],
+  };
   const testRow2: LogRowModel = {
     rowIndex: 0,
     entryFieldIndex: -1,