Describe the main idea in readme or contribution guide (#545)

* Add standard test

* Fix test

README.md

@@ -39,8 +39,8 @@ For **Java 8** compatible version take a look at release [0.7.0](https://github.
 All checks can be divided into 2 groups:
 
 1. Runtime checks (those that make sense to perform only on a production database with real data and statistics).  
-   Runtime checks usually [require aggregating data from all nodes in the cluster](https://github.com/mfvanek/pg-index-health/blob/d1473dc68975ebe932d92c9e43ceebde657d0cc7/pg-index-health-core/src/main/java/io/github/mfvanek/pg/common/maintenance/Diagnostic.java#L162).
-   This necessitated creating [our own abstraction over the database connection](https://github.com/mfvanek/pg-index-health/tree/master/pg-index-health-jdbc-connection).
+   Runtime checks usually [require aggregating data from all nodes in the cluster](https://github.com/mfvanek/pg-index-health/blob/3e9a63cc2a04799f3e97c9bec9b684ababca8db7/pg-index-health-core/src/main/java/io/github/mfvanek/pg/core/checks/common/Diagnostic.java#L162).
+   This necessitated creating [our own abstraction over the database connection](https://github.com/mfvanek/pg-index-health/blob/3e9a63cc2a04799f3e97c9bec9b684ababca8db7/pg-index-health-jdbc-connection/src/main/java/io/github/mfvanek/pg/connection/HighAvailabilityPgConnection.java#L22).
 2. Static checks (those can be run in tests on an empty database).  
    All static checks can be performed at runtime as well.
 
@@ -81,14 +81,15 @@ For raw sql queries see [pg-index-health-sql](https://github.com/mfvanek/pg-inde
 ### Static checks
 
 Static checks are based on [information schema](https://www.postgresql.org/docs/current/information-schema.html)/[system catalogs](https://www.postgresql.org/docs/current/catalogs.html).
+They work with finite database state (after all migrations are applied).
 
 ### Runtime checks
 
 **pg_index_health** utilizes [the Cumulative Statistics System](https://www.postgresql.org/docs/current/monitoring-stats.html) 
 (formerly known as [PostgreSQL's statistics collector](https://www.postgresql.org/docs/14/monitoring-stats.html)).
 
 You can call `pg_stat_reset()` on each host to reset all statistics counters for the current database to zero
-but the best way to do it is to use [DatabaseManagement::resetStatistics()](https://github.com/mfvanek/pg-index-health/blob/d1473dc68975ebe932d92c9e43ceebde657d0cc7/pg-index-health/src/main/java/io/github/mfvanek/pg/common/management/DatabaseManagement.java#L33) method.
+but the best way to do it is to use [DatabaseManagement::resetStatistics()](https://github.com/mfvanek/pg-index-health/blob/3e9a63cc2a04799f3e97c9bec9b684ababca8db7/pg-index-health/src/main/java/io/github/mfvanek/pg/health/checks/management/DatabaseManagement.java#L33) method.
 
 ## Installation
 
@@ -116,12 +117,15 @@ Using Maven:
 
 ## Articles and publications
 
+### In Russian
 * [Index health in PostgreSQL through the eyes of a Java developer](https://habr.com/ru/post/490824/)
+* [DBA: finding useless indexes](https://habr.com/ru/companies/tensor/articles/488104/)
+* [The series of articles "Static analysis of the database structure"](https://habr.com/ru/articles/800121/)
 
 ## How to use
 
 There are three main scenarios of using **pg-index-health** in your projects:
-* unit\functional testing;
+* unit\functional testing (see **standard test** in section below);
 * collecting indexes health data and monitoring bloat;
 * analysis of database configuration.
 
@@ -161,6 +165,45 @@ Using Maven:
 </dependency>
 ```
 
+### Standard test
+
+Add a standard test to your project as shown below. Ideally, all checks should work and return an empty result.
+
+```java
+import io.github.mfvanek.pg.core.checks.common.DatabaseCheckOnHost;
+import io.github.mfvanek.pg.core.checks.common.Diagnostic;
+import io.github.mfvanek.pg.model.dbobject.DbObject;
+import org.junit.jupiter.api.Test;
+import org.springframework.beans.factory.annotation.Autowired;
+import org.springframework.boot.test.context.SpringBootTest;
+import org.springframework.test.context.ActiveProfiles;
+
+import java.util.List;
+
+import static org.assertj.core.api.Assertions.assertThat;
+
+@SpringBootTest
+@ActiveProfiles("test")
+class DatabaseStructureStaticAnalysisTest {
+
+    @Autowired
+    private List<DatabaseCheckOnHost<? extends DbObject>> checks;
+
+    @Test
+    void checksShouldWork() {
+        assertThat(checks)
+            .hasSameSizeAs(Diagnostic.values());
+
+        checks.stream()
+            .filter(DatabaseCheckOnHost::isStatic)
+            .forEach(c ->
+                assertThat(c.check())
+                    .as(c.getDiagnostic().name())
+                    .isEmpty());
+    }
+}
+```
+
 ### Spring Boot compatibility
 
 | Spring Boot | Min JDK | pg-index-health-test-starter |

spring-boot-integration/h2-demo-app/src/test/java/io/github/mfvanek/pg/spring/h2/H2DemoApplicationTest.java

@@ -20,8 +20,8 @@
 
 import static org.assertj.core.api.Assertions.assertThat;
 
-@ActiveProfiles("test")
 @SpringBootTest
+@ActiveProfiles("test")
 class H2DemoApplicationTest {
 
     @Autowired

spring-boot-integration/kotlin-custom-ds-demo-app/src/test/kotlin/io/github/mfvanek/pg/spring/postgres/kt/custom/ds/DatabaseStructureStaticAnalysisTest.kt

@@ -0,0 +1,55 @@
+/*
+ * Copyright (c) 2019-2024. Ivan Vakhrushev and others.
+ * https://github.com/mfvanek/pg-index-health
+ *
+ * This file is a part of "pg-index-health" - a Java library for
+ * analyzing and maintaining indexes health in PostgreSQL databases.
+ *
+ * Licensed under the Apache License 2.0
+ */
+
+package io.github.mfvanek.pg.spring.postgres.kt.custom.ds
+
+import io.github.mfvanek.pg.core.checks.common.DatabaseCheckOnHost
+import io.github.mfvanek.pg.core.checks.common.Diagnostic
+import io.github.mfvanek.pg.model.context.PgContext
+import io.github.mfvanek.pg.model.dbobject.DbObject
+import io.github.mfvanek.pg.model.predicates.SkipLiquibaseTablesPredicate
+import io.github.mfvanek.pg.model.table.Table
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.test.context.ActiveProfiles
+
+@SpringBootTest
+@ActiveProfiles("test")
+internal class DatabaseStructureStaticAnalysisTest {
+
+    @Autowired
+    private lateinit var checks: List<DatabaseCheckOnHost<out DbObject?>>
+
+    @Test
+    fun checksShouldWork() {
+        assertThat(checks)
+            .hasSameSizeAs(Diagnostic.entries.toTypedArray())
+
+        checks
+            .filter { it.isStatic }
+            .forEach { check ->
+                val ctx = PgContext.of("custom_ds_schema")
+                // Due to the use of spring.liquibase.default-schema, all names are resolved without a schema
+                val listAssert = assertThat(check.check(ctx, SkipLiquibaseTablesPredicate.ofPublic()))
+                    .`as`(check.diagnostic.name)
+
+                when (check.diagnostic) {
+                    Diagnostic.TABLES_NOT_LINKED_TO_OTHERS ->
+                        listAssert
+                            .hasSize(1)
+                            .containsExactly(Table.of("warehouse"))
+
+                    else -> listAssert.isEmpty()
+                }
+            }
+    }
+}

spring-boot-integration/kotlin-custom-ds-demo-app/src/test/kotlin/io/github/mfvanek/pg/spring/postgres/kt/custom/ds/PostgresCustomDataSourceDemoApplicationKtRunTest.kt

@@ -17,7 +17,6 @@ internal class PostgresCustomDataSourceDemoApplicationKtRunTest {
         assertThat(output.all)
             .contains("Reading from custom_ds_schema.databasechangelog")
             .contains("Starting PostgresCustomDataSourceDemoApplicationKt using Java")
-            .contains("Container is started (JDBC URL: jdbc:postgresql://localhost:")
             .contains("Started PostgresCustomDataSourceDemoApplicationKt in")
     }
 }

spring-boot-integration/kotlin-custom-ds-demo-app/src/test/kotlin/io/github/mfvanek/pg/spring/postgres/kt/custom/ds/PostgresCustomDataSourceDemoApplicationKtTest.kt

@@ -2,29 +2,20 @@ package io.github.mfvanek.pg.spring.postgres.kt.custom.ds
 
 import com.zaxxer.hikari.HikariDataSource
 import io.github.mfvanek.pg.connection.PgConnection
-import io.github.mfvanek.pg.core.checks.common.DatabaseCheckOnHost
-import io.github.mfvanek.pg.core.checks.common.Diagnostic
-import io.github.mfvanek.pg.model.context.PgContext
-import io.github.mfvanek.pg.model.dbobject.DbObject
-import io.github.mfvanek.pg.model.predicates.SkipLiquibaseTablesPredicate
-import io.github.mfvanek.pg.model.table.Table
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 import org.springframework.beans.factory.annotation.Autowired
 import org.springframework.boot.test.context.SpringBootTest
 import org.springframework.context.ApplicationContext
 import org.springframework.test.context.ActiveProfiles
 
-@ActiveProfiles("test")
 @SpringBootTest
+@ActiveProfiles("test")
 internal class PostgresCustomDataSourceDemoApplicationKtTest {
 
     @Autowired
     private lateinit var applicationContext: ApplicationContext
 
-    @Autowired
-    private lateinit var checks: List<DatabaseCheckOnHost<out DbObject?>>
-
     @Test
     fun contextLoadsAndContainsPgIndexHealthBeans() {
         assertThat(applicationContext.getBean("pgihCustomDataSource"))
@@ -33,28 +24,4 @@ internal class PostgresCustomDataSourceDemoApplicationKtTest {
         assertThat(applicationContext.getBean("pgConnection"))
             .isInstanceOf(PgConnection::class.java)
     }
-
-    @Test
-    fun checksShouldWork() {
-        assertThat(checks)
-            .hasSameSizeAs(Diagnostic.entries.toTypedArray())
-
-        checks
-            .filter { it.isStatic }
-            .forEach { check ->
-                val ctx = PgContext.of("custom_ds_schema")
-                // Due to the use of spring.liquibase.default-schema, all names are resolved without a schema
-                val listAssert = assertThat(check.check(ctx, SkipLiquibaseTablesPredicate.ofPublic()))
-                    .`as`(check.diagnostic.name)
-
-                when (check.diagnostic) {
-                    Diagnostic.TABLES_NOT_LINKED_TO_OTHERS ->
-                        listAssert
-                            .hasSize(1)
-                            .containsExactly(Table.of("warehouse"))
-
-                    else -> listAssert.isEmpty()
-                }
-            }
-    }
 }

spring-boot-integration/kotlin-demo-app/src/test/kotlin/io/github/mfvanek/pg/spring/postgres/kt/DatabaseStructureStaticAnalysisTest.kt

@@ -0,0 +1,42 @@
+/*
+ * Copyright (c) 2019-2024. Ivan Vakhrushev and others.
+ * https://github.com/mfvanek/pg-index-health
+ *
+ * This file is a part of "pg-index-health" - a Java library for
+ * analyzing and maintaining indexes health in PostgreSQL databases.
+ *
+ * Licensed under the Apache License 2.0
+ */
+
+package io.github.mfvanek.pg.spring.postgres.kt
+
+import io.github.mfvanek.pg.core.checks.common.DatabaseCheckOnHost
+import io.github.mfvanek.pg.core.checks.common.Diagnostic
+import io.github.mfvanek.pg.model.dbobject.DbObject
+import org.assertj.core.api.Assertions.assertThat
+import org.junit.jupiter.api.Test
+import org.springframework.beans.factory.annotation.Autowired
+import org.springframework.boot.test.context.SpringBootTest
+import org.springframework.test.context.ActiveProfiles
+
+@SpringBootTest
+@ActiveProfiles("test")
+internal class DatabaseStructureStaticAnalysisTest {
+
+    @Autowired
+    private lateinit var checks: List<DatabaseCheckOnHost<out DbObject?>>
+
+    @Test
+    fun checksShouldWork() {
+        assertThat(checks)
+            .hasSameSizeAs(Diagnostic.entries.toTypedArray())
+
+        checks
+            .filter { it.isStatic }
+            .forEach {
+                assertThat(it.check())
+                    .`as`(it.diagnostic.name)
+                    .isEmpty()
+            }
+    }
+}

spring-boot-integration/kotlin-demo-app/src/test/kotlin/io/github/mfvanek/pg/spring/postgres/kt/PostgresDemoApplicationKtTest.kt

@@ -12,9 +12,6 @@ package io.github.mfvanek.pg.spring.postgres.kt
 
 import com.zaxxer.hikari.HikariDataSource
 import io.github.mfvanek.pg.connection.PgConnection
-import io.github.mfvanek.pg.core.checks.common.DatabaseCheckOnHost
-import io.github.mfvanek.pg.core.checks.common.Diagnostic
-import io.github.mfvanek.pg.model.dbobject.DbObject
 import org.assertj.core.api.Assertions.assertThat
 import org.junit.jupiter.api.Test
 import org.springframework.beans.factory.annotation.Autowired
@@ -23,8 +20,8 @@ import org.springframework.context.ApplicationContext
 import org.springframework.core.env.Environment
 import org.springframework.test.context.ActiveProfiles
 
-@ActiveProfiles("test")
 @SpringBootTest
+@ActiveProfiles("test")
 internal class PostgresDemoApplicationKtTest {
 
     @Autowired
@@ -33,9 +30,6 @@ internal class PostgresDemoApplicationKtTest {
     @Autowired
     private lateinit var environment: Environment
 
-    @Autowired
-    private lateinit var checks: List<DatabaseCheckOnHost<out DbObject?>>
-
     @Test
     fun contextLoadsAndContainsPgIndexHealthBeans() {
         assertThat(applicationContext.getBean("dataSource"))
@@ -49,18 +43,4 @@ internal class PostgresDemoApplicationKtTest {
             .startsWith("jdbc:postgresql://localhost:")
             .endsWith("/demo_for_pg_index_health_starter?loggerLevel=OFF")
     }
-
-    @Test
-    fun checksShouldWork() {
-        assertThat(checks)
-            .hasSameSizeAs(Diagnostic.entries.toTypedArray())
-
-        checks
-            .filter { it.isStatic }
-            .forEach {
-                assertThat(it.check())
-                    .`as`(it.diagnostic.name)
-                    .isEmpty()
-            }
-    }
 }