Fixing docs and tests for timeseries no-longer-snapshot functions (elastic#135395)

* Fixing docs and tests for timeseries no-longer-snapshot functions

* regen rate.md

Author: pabloem

docs/reference/query-languages/esql/_snippets/functions/description/rate.md

@@ -46,7 +46,7 @@ public class Delta extends TimeSeriesAggregateFunction implements OptionalArgume
         returnType = { "double" },
         description = "The absolute change of a gauge field in a time window.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.UNAVAILABLE) },
-        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command in snapshot builds"
+        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command"
     )
     public Delta(Source source, @Param(name = "field", type = { "long", "integer", "double" }) Expression field) {
         this(source, field, new UnresolvedAttribute(source, "@timestamp"));

docs/reference/query-languages/esql/kibana/definition/functions/rate.json

@@ -48,7 +48,7 @@ public class Idelta extends TimeSeriesAggregateFunction implements OptionalArgum
             + "it ignores all but the last two data points in each time period). "
             + "This function is very similar to delta, but is more responsive to recent changes.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.UNAVAILABLE) },
-        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command in snapshot builds"
+        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command"
     )
     public Idelta(Source source, @Param(name = "field", type = { "long", "integer", "double" }) Expression field) {
         this(source, field, new UnresolvedAttribute(source, "@timestamp"));

docs/reference/query-languages/esql/kibana/docs/functions/rate.md

@@ -51,7 +51,7 @@ public class Increase extends TimeSeriesAggregateFunction implements OptionalArg
         returnType = { "double" },
         description = "The absolute increase of a counter field in a time window.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.UNAVAILABLE) },
-        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command in snapshot builds"
+        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command"
     )
     public Increase(
         Source source,

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Delta.java

@@ -48,7 +48,7 @@ public class Irate extends TimeSeriesAggregateFunction implements OptionalArgume
             + "it ignores all but the last two data points in each time period). "
             + "This function is very similar to rate, but is more responsive to recent changes in the rate of increase.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.UNAVAILABLE) },
-        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command in snapshot builds",
+        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command",
         examples = { @Example(file = "k8s-timeseries", tag = "irate") }
     )
     public Irate(Source source, @Param(name = "field", type = { "counter_long", "counter_integer", "counter_double" }) Expression field) {

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Idelta.java

@@ -46,7 +46,7 @@ public class Rate extends TimeSeriesAggregateFunction implements OptionalArgumen
         returnType = { "double" },
         description = "The rate of a counter field.",
         appliesTo = { @FunctionAppliesTo(lifeCycle = FunctionAppliesToLifecycle.UNAVAILABLE) },
-        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command in snapshot builds",
+        note = "Available with the [TS](/reference/query-languages/esql/commands/source-commands.md#esql-ts) command",
         examples = { @Example(file = "k8s-timeseries", tag = "rate") }
     )
     public Rate(Source source, @Param(name = "field", type = { "counter_long", "counter_integer", "counter_double" }) Expression field) {

x-pack/plugin/esql/src/main/java/org/elasticsearch/xpack/esql/expression/function/aggregate/Increase.java

@@ -241,7 +241,7 @@ setup:
 
   # There's one of these per function but that's a ton of things to check. So we just spot check that a few exist.
   - not_exists: esql.functions.delay
-  - not_exists: esql.functions.idelta
+  - exists: esql.functions.idelta
   - exists: esql.functions.mv_sum
   - exists: esql.functions.to_dateperiod