Preserve liquibase.shouldSnapshotData in the CLI

[nvoxland]

Description

When using the CLI, if you set --should-snapshot-data=true but do NOT include a --data-dir flag in generate-changelog, you do not get data included in the generated changelog.

Repo Steps

Populate a database like:

create table test_table (id int);

insert into test_table values (1);
insert into test_table values (2);

Run liquibase --should-snapshot-data=true generate-changelog --changelog-file=out.xml

Expected
out.xml will include <insert> tags for test_table

Actual
output.xml does not include <insert> tags.

[nvoxland]

I looked at adding a test to generateChangelog.test.groovy, but because whether Data is snapshotted by default is managed by a singleton, changing the liquibase.shouldSnapshotData flag during the test run doesn't get taken into account. Because of that, I couldn't find a good way to test it through the existing automation.

So, while this does happen to fix the CLI problem because we just run through the logic once, there is a larger problem on respecting that flag as it changes over time we should address at some point.

[XDelphiGrl]

This impacts generate-changelog data snapshot behavior. The --should-snapshot-data CLI property is preserved, even when the --data-output-directory property is not specified in the command. Structured changelog formats (XML, YML, JSON) include insert changetypes; the formatted SQL changelog contains insert statements.

Notes

• There is a mistake in the official Liquibase documentation indicating the --should-snapshot-data is compatible with the snapshot command. This is not true and we will update the documentation. The only command that "gathers" data is generate-changelog.
• GitHub issue describes the limitation of snapshot and --should-snapshot-data.

---

Verify generate-changelog includes insert changetypes for data when --should-snapshot-data true. PASS

• XML PASS

    <changeSet author="erz (generated)" id="1645547823225-3">
        <insert tableName="pr2542">
            <column name="id" valueNumeric="1"/>
        </insert>
        <insert tableName="pr2542">
            <column name="id" valueNumeric="2"/>
        </insert>
    </changeSet>

• JSON PASS

  {
    "changeSet": {
      "id": "1645547851009-3",
      "author": "erz (generated)",
      "changes": [
        {
          "insert": {
            "columns": [
              {
                "column": {
                  "name": "id",
                  "valueNumeric": 1
                }
              }]
            ,
            "tableName": "pr2542"
          }
        },
        {
          "insert": {
            "columns": [
              {
                "column": {
                  "name": "id",
                  "valueNumeric": 2
                }
              }]
            ,
            "tableName": "pr2542"
          }
        }]
      
    }
  }

• SQL PASS

-- changeset erz:1645547865549-3
INSERT INTO pr2542 (id) VALUES (1);
INSERT INTO pr2542 (id) VALUES (2);

• YML PASS

- changeSet:
    id: 1645547839194-3
    author: erz (generated)
    changes:
    - insert:
        columns:
        - column:
            name: id
            valueNumeric: 1
        tableName: pr2542
    - insert:
        columns:
        - column:
            name: id
            valueNumeric: 2
        tableName: pr2542

Verify generate-changelog outputs a csv file when --should-snapshot-data true AND --data-output-directory <someDir>. PASS

Verify generate-changelog includes loadData changetypes when should-snapshot-data true AND --data-output-directory <someDir>.

• XML PASS
• YML PASS
• JSON PASS

I also validated update-sql, update and diff using the XML created with generate-changelog and should-snapshot-data (no data directory specified); everything worked as expected.

---

Test Environment
Liquibase Core: respect-should-snapshot-data/1528/224e5e, Pro: master/591/f653ec
MySQL 8.0
Windows 10
Passing Functional Tests
Internal Functional Test PR