use top instead of limit in dbt show and adapt tests

dbt/include/synapse/macros/adapters/show.sql

@@ -0,0 +1,22 @@
+{% macro get_show_sql(compiled_code, sql_header, limit) -%}
+  {%- if sql_header -%}
+  {{ sql_header }}
+  {%- endif -%}
+  {%- if limit is not none -%}
+  {{ get_limit_subquery_sql(compiled_code, limit) }}
+  {%- else -%}
+  {{ compiled_code }}
+  {%- endif -%}
+{% endmacro %}
+
+{% macro get_limit_subquery_sql(sql, limit) %}
+  {{ adapter.dispatch('get_limit_subquery_sql', 'dbt')(sql, limit) }}
+{% endmacro %}
+
+{# Synapse doesnt support ANSI LIMIT clause #}
+{% macro synapse__get_limit_subquery_sql(sql, limit) %}
+    select top {{ limit }} *
+    from (
+        {{ sql }}
+    ) as model_limit_subq
+{% endmacro %}

tests/functional/adapter/test_dbt_show.py

@@ -0,0 +1,70 @@
+import pytest
+from dbt.tests.adapter.dbt_show.test_dbt_show import (
+    models__sample_model,
+    models__sql_header,
+    seeds__sample_seed,
+)
+from dbt.tests.util import run_dbt
+
+models__sample_model_a = """
+select
+    coalesce(sample_num, 0) + 10 as col_deci
+from {{ ref('sample_model') }}
+"""
+
+models__sample_model_b = """
+select
+    col_deci + 100 as col_hundo
+from {{ ref('sample_model_a') }}
+"""
+
+
+# Synapse doesn't support ephemeral models so we need to alter the base tests
+class BaseShowLimit:
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "sample_model.sql": models__sample_model,
+            "sample_model_a.sql": models__sample_model_a,
+        }
+
+    @pytest.fixture(scope="class")
+    def seeds(self):
+        return {"sample_seed.csv": seeds__sample_seed}
+
+    @pytest.mark.parametrize(
+        "args,expected",
+        [
+            ([], 5),  # default limit
+            (["--limit", 3], 3),  # fetch 3 rows
+            (["--limit", -1], 7),  # fetch all rows
+        ],
+    )
+    def test_limit(self, project, args, expected):
+        run_dbt(["build"])
+        dbt_args = ["show", "--inline", models__sample_model_b, *args]
+        results = run_dbt(dbt_args)
+        assert len(results.results[0].agate_table) == expected
+        # ensure limit was injected in compiled_code when limit specified in command args
+        limit = results.args.get("limit")
+        if limit > 0:
+            assert f"top {limit}" in results.results[0].node.compiled_code
+
+
+class BaseShowSqlHeader:
+    @pytest.fixture(scope="class")
+    def models(self):
+        return {
+            "sql_header.sql": models__sql_header,
+        }
+
+    def test_sql_header(self, project):
+        run_dbt(["show", "--select", "sql_header", "--vars", "timezone: Asia/Kolkata"])
+
+
+class TestShowSqlHeaderSynapse(BaseShowSqlHeader):
+    pass
+
+
+class TestShowLimitSynapse(BaseShowLimit):
+    pass