InfluxDB: Fix for wrong query generated with template variable and non regex operator on frontend mode (#84175)

* fix for wrong query generated for influxdb. see:https://github.com/grafana/grafana/issues/81517

Signed-off-by: Syed Nihal <syed.nihal@nokia.com>

* added unit tests

Signed-off-by: Syed Nihal <syed.nihal@nokia.com>

* fixed linting

Signed-off-by: Syed Nihal <syed.nihal@nokia.com>

* addressed review comments

Signed-off-by: Syed Nihal <syed.nihal@nokia.com>

* fixed linting issue

Signed-off-by: Syed Nihal <syed.nihal@nokia.com>

---------

Signed-off-by: Syed Nihal <syed.nihal@nokia.com>

public/app/plugins/datasource/influxdb/influx_query_model.test.ts

@@ -604,4 +604,53 @@ describe('InfluxQuery', () => {
       });
     });
   });
+
+  describe('test query generated with templateVariable and non-regex operator', () => {
+    const testCases = [
+      ['=', 'SELECT mean("value") FROM "autogen"."cpu" WHERE ("value" = \'$tempVar\') AND $timeFilter'],
+      ['!=', 'SELECT mean("value") FROM "autogen"."cpu" WHERE ("value" != \'$tempVar\') AND $timeFilter'],
+      ['Is', 'SELECT mean("value") FROM "autogen"."cpu" WHERE ("value" = \'$tempVar\') AND $timeFilter'],
+      ['Is Not', 'SELECT mean("value") FROM "autogen"."cpu" WHERE ("value" != \'$tempVar\') AND $timeFilter'],
+      ['>', 'SELECT mean("value") FROM "autogen"."cpu" WHERE ("value" > $tempVar) AND $timeFilter'],
+      ['<', 'SELECT mean("value") FROM "autogen"."cpu" WHERE ("value" < $tempVar) AND $timeFilter'],
+    ];
+
+    it.each(testCases)('should not wrap with InfluxDB regex wrapper for "%s" operator', (operator, expectedQuery) => {
+      const query = new InfluxQueryModel(
+        {
+          refId: 'A',
+          measurement: 'cpu',
+          policy: 'autogen',
+          groupBy: [],
+          tags: [{ key: 'value', value: '/^$tempVar$/', operator }],
+        },
+        templateSrv,
+        {}
+      );
+      const queryText = query.render();
+      expect(queryText).toBe(expectedQuery);
+    });
+  });
+  describe('test query generated with templateVariable and regex operator', () => {
+    const testCases = [
+      ['=~', 'SELECT mean("value") FROM "autogen"."cpu" WHERE ("value" =~ /^$tempVar$/) AND $timeFilter'],
+      ['!~', 'SELECT mean("value") FROM "autogen"."cpu" WHERE ("value" !~ /^$tempVar$/) AND $timeFilter'],
+    ];
+
+    it.each(testCases)('should wrap with InfluxDB regex wrapper for "%s" operator', (operator, expectedQuery) => {
+      const query = new InfluxQueryModel(
+        {
+          refId: 'A',
+          measurement: 'cpu',
+          policy: 'autogen',
+          groupBy: [],
+          tags: [{ key: 'value', value: '/^$tempVar$/', operator }],
+        },
+        templateSrv,
+        {}
+      );
+      const queryText = query.render();
+      expect(queryText).toBe(expectedQuery);
+    });
+  });
 });

public/app/plugins/datasource/influxdb/influx_query_model.ts

@@ -141,6 +141,17 @@ export default class InfluxQueryModel {
     this.updatePersistedParts();
   }
 
+  private removeRegexWrapper(str: string) {
+    const regex = /\/\^(.*?)\$\//; // match any string that starts with "/^" and ends with "$/", capturing the characters in between
+    const match = str.match(regex);
+
+    if (match && match.length > 1) {
+      return match[1];
+    } else {
+      return str;
+    }
+  }
+
   private isOperatorTypeHandler(operator: string, value: string, fieldName: string) {
     let textValue;
     if (operator === 'Is Not') {
@@ -151,7 +162,7 @@ export default class InfluxQueryModel {
 
     // Tags should always quote
     if (fieldName.endsWith('::tag')) {
-      textValue = "'" + value.replace(/\\/g, '\\\\').replace(/\'/g, "\\'") + "'";
+      textValue = "'" + this.removeRegexWrapper(value.replace(/\\/g, '\\\\').replace(/\'/g, "\\'")) + "'";
       return {
         operator: operator,
         value: textValue,
@@ -169,7 +180,7 @@ export default class InfluxQueryModel {
       textValue = lowerValue;
     } else {
       // String or unrecognised: quote
-      textValue = "'" + value.replace(/\\/g, '\\\\').replace(/\'/g, "\\'") + "'";
+      textValue = "'" + this.removeRegexWrapper(value.replace(/\\/g, '\\\\').replace(/\'/g, "\\'")) + "'";
     }
     return {
       operator: operator,
@@ -199,7 +210,7 @@ export default class InfluxQueryModel {
       if (interpolate) {
         value = this.templateSrv.replace(value, this.scopedVars);
       }
-
+      value = this.removeRegexWrapper(value);
       if (operator.startsWith('Is')) {
         let r = this.isOperatorTypeHandler(operator, value, tag.key);
         operator = r.operator;