test: Add datafusion-cli fair and unbounded memory-pool test coverage (#20565)

## Which issue does this PR close?
- Closes #20564.

## Rationale for this change
Currently, `datafusion-cli` submodule does not have test coverage for
`--mem-pool-type = fair / unbounded` (default: `greedy` and `unbounded`
memory pool is used when both `--memory-limit` and `--mem-pool-type` are
`not` set). Legacy test cases use `greedy` memory pool by setting
`--memory-limit`. This PR aims to cover `--mem-pool-type = fair /
unbounded` cases with `--memory-limit` and `--top-memory-consumers`
usages. Also, `datafusion-cli` is a client used by end-users so
extending test coverages of the exposed features can be useful for the
functional verification and long-term maintenance.

**Case1:** `fair` memory pool usage by `datafusion-cli` when
`top-memory-consumers = 0` (Top Memory Consumers will not be listed when
memory is exhausted)
```
program: datafusion-cli
  args:
    - "--memory-limit"
    - 10M
    - "--mem-pool-type"
    - fair
    - "--command"
    - "select * from generate_series(1,500000) as t1(v1) order by v1;"
    - "--top-memory-consumers"
    - "0"
```

**Case2:** `fair` memory pool usage by `datafusion-cli` when
`top-memory-consumers > 0` (Top Memory Consumers will be listed when
memory is exhausted)
```
program: datafusion-cli
  args:
    - "--memory-limit"
    - 10M
    - "--mem-pool-type"
    - fair
    - "--command"
    - "select * from generate_series(1,500000) as t1(v1) order by v1;"
    - "--top-memory-consumers"
    - "2"
```

**Case3:** `unbounded` memory pool usage by `datafusion-cli`
```
program: datafusion-cli
  args:
    - "--maxrows"
    - "10"
    - "--command"
    - "select * from generate_series(1,500000) as t1(v1) order by v1;"
```

## What changes are included in this PR?
Explained under above section.

## Are these changes tested?
Yes, being added new integration tests and they are successful locally:
```
test test_cli_top_memory_consumers_with_mem_pool_type::case_1 ... ok
test test_cli_top_memory_consumers_with_mem_pool_type::case_2 ... ok
test test_cli_with_unbounded_memory_pool::case_1 ... ok
```

## Are there any user-facing changes?
No

Author: erenavsarogullari

datafusion-cli/tests/cli_integration.rs

@@ -20,6 +20,7 @@ use std::process::Command;
 use rstest::rstest;
 
 use async_trait::async_trait;
+use insta::internals::SettingsBindDropGuard;
 use insta::{Settings, glob};
 use insta_cmd::{assert_cmd_snapshot, get_cargo_bin};
 use std::path::PathBuf;
@@ -215,6 +216,42 @@ fn test_cli_top_memory_consumers<'a>(
     #[case] snapshot_name: &str,
     #[case] top_memory_consumers: impl IntoIterator<Item = &'a str>,
 ) {
+    let _bound = bind_to_settings(snapshot_name);
+
+    let mut cmd = cli();
+    let sql = "select * from generate_series(1,500000) as t1(v1) order by v1;";
+    cmd.args(["--memory-limit", "10M", "--command", sql]);
+    cmd.args(top_memory_consumers);
+
+    assert_cmd_snapshot!(cmd);
+}
+
+#[rstest]
+#[case("no_track", ["--top-memory-consumers", "0"])]
+#[case("top2", ["--top-memory-consumers", "2"])]
+#[test]
+fn test_cli_top_memory_consumers_with_mem_pool_type<'a>(
+    #[case] snapshot_name: &str,
+    #[case] top_memory_consumers: impl IntoIterator<Item = &'a str>,
+) {
+    let _bound = bind_to_settings(snapshot_name);
+
+    let mut cmd = cli();
+    let sql = "select * from generate_series(1,500000) as t1(v1) order by v1;";
+    cmd.args([
+        "--memory-limit",
+        "10M",
+        "--mem-pool-type",
+        "fair",
+        "--command",
+        sql,
+    ]);
+    cmd.args(top_memory_consumers);
+
+    assert_cmd_snapshot!(cmd);
+}
+
+fn bind_to_settings(snapshot_name: &str) -> SettingsBindDropGuard {
     let mut settings = make_settings();
 
     settings.set_snapshot_suffix(snapshot_name);
@@ -232,12 +269,20 @@ fn test_cli_top_memory_consumers<'a>(
         "Resources exhausted: Failed to allocate",
     );
 
+    settings.bind_to_scope()
+}
+
+#[test]
+fn test_cli_with_unbounded_memory_pool() {
+    let mut settings = make_settings();
+
+    settings.set_snapshot_suffix("default");
+
     let _bound = settings.bind_to_scope();
 
     let mut cmd = cli();
     let sql = "select * from generate_series(1,500000) as t1(v1) order by v1;";
-    cmd.args(["--memory-limit", "10M", "--command", sql]);
-    cmd.args(top_memory_consumers);
+    cmd.args(["--maxrows", "10", "--command", sql]);
 
     assert_cmd_snapshot!(cmd);
 }

datafusion-cli/tests/snapshots/cli_top_memory_consumers_with_mem_pool_type@no_track.snap

@@ -0,0 +1,23 @@
+---
+source: datafusion-cli/tests/cli_integration.rs
+info:
+  program: datafusion-cli
+  args:
+    - "--memory-limit"
+    - 10M
+    - "--mem-pool-type"
+    - fair
+    - "--command"
+    - "select * from generate_series(1,500000) as t1(v1) order by v1;"
+    - "--top-memory-consumers"
+    - "0"
+---
+success: false
+exit_code: 1
+----- stdout -----
+[CLI_VERSION]
+Error: Not enough memory to continue external sort. Consider increasing the memory limit config: 'datafusion.runtime.memory_limit', or decreasing the config: 'datafusion.execution.sort_spill_reservation_bytes'.
+caused by
+Resources exhausted: Failed to allocate
+
+----- stderr -----

datafusion-cli/tests/snapshots/cli_top_memory_consumers_with_mem_pool_type@top2.snap

@@ -0,0 +1,26 @@
+---
+source: datafusion-cli/tests/cli_integration.rs
+info:
+  program: datafusion-cli
+  args:
+    - "--memory-limit"
+    - 10M
+    - "--mem-pool-type"
+    - fair
+    - "--command"
+    - "select * from generate_series(1,500000) as t1(v1) order by v1;"
+    - "--top-memory-consumers"
+    - "2"
+---
+success: false
+exit_code: 1
+----- stdout -----
+[CLI_VERSION]
+Error: Not enough memory to continue external sort. Consider increasing the memory limit config: 'datafusion.runtime.memory_limit', or decreasing the config: 'datafusion.execution.sort_spill_reservation_bytes'.
+caused by
+Resources exhausted: Additional allocation failed for ExternalSorter[0] with top memory consumers (across reservations) as:
+  Consumer(can spill: bool) consumed XB, peak XB,
+  Consumer(can spill: bool) consumed XB, peak XB.
+Error: Failed to allocate 
+
+----- stderr -----

datafusion-cli/tests/snapshots/cli_with_unbounded_memory_pool@default.snap

@@ -0,0 +1,36 @@
+---
+source: datafusion-cli/tests/cli_integration.rs
+info:
+  program: datafusion-cli
+  args:
+    - "--maxrows"
+    - "10"
+    - "--command"
+    - "select * from generate_series(1,500000) as t1(v1) order by v1;"
+---
+success: true
+exit_code: 0
+----- stdout -----
+[CLI_VERSION]
++----+
+| v1 |
++----+
+| 1  |
+| 2  |
+| 3  |
+| 4  |
+| 5  |
+| 6  |
+| 7  |
+| 8  |
+| 9  |
+| 10 |
+| .  |
+| .  |
+| .  |
++----+
+500000 row(s) fetched. (First 10 displayed. Use --maxrows to adjust)
+[ELAPSED]
+
+
+----- stderr -----