Merge b8162e8075 into 40b9536ce5

fix: Maven Toolchains grows unexpectedly
On self-hosted runners toolchains.xml may survive multiple runs and unexpectedly grow as a result of the toolchains setup simply appending the JDK definition even if one with the same `type` and `provides.id` already exists. Restructuring the parsing step and filtering the potentially existing list of toolchain definitions prevents this and also fixes toolchain.xml files that already contain duplicates. Fixes #530
2024-11-13 21:48:05 +00:00 · 2024-09-22 22:59:54 +02:00 · 2023-12-09 11:34:18 +01:00
3 changed files with 563 additions and 76 deletions
--- a/tests/toolchains.test.ts
+++ b/tests/toolchains.test.ts
@ -143,7 +143,20 @@ describe('toolchains tests', () => {
        </toolchain>
      </toolchains>`;
    const result = `<?xml version="1.0"?>
-<toolchains>
+<toolchains xmlns="http://maven.apache.org/TOOLCHAINS/1.1.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd">
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>17</version>
+      <vendor>Eclipse Temurin</vendor>
+      <id>temurin_17</id>
+    </provides>
+    <configuration>
+      <jdkHome>/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64</jdkHome>
+    </configuration>
+  </toolchain>
  <toolchain>
    <type>jdk</type>
    <provides>
@ -155,6 +168,442 @@ describe('toolchains tests', () => {
      <jdkHome>/opt/jdk/sun/1.6</jdkHome>
    </configuration>
  </toolchain>
+</toolchains>`;
+
+    fs.mkdirSync(m2Dir, {recursive: true});
+    fs.writeFileSync(toolchainsFile, originalFile);
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+
+    await toolchains.createToolchainsSettings({
+      jdkInfo,
+      settingsDirectory: m2Dir,
+      overwriteSettings: true
+    });
+
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+    expect(fs.readFileSync(toolchainsFile, 'utf-8')).toEqual(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    );
+    expect(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    ).toEqual(result);
+  }, 100000);
+
+  it('does not discard custom elements in existing toolchain definitions', async () => {
+    const jdkInfo = {
+      version: '17',
+      vendor: 'Eclipse Temurin',
+      id: 'temurin_17',
+      jdkHome: '/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64'
+    };
+
+    const originalFile = `<toolchains>
+        <toolchain>
+          <type>jdk</type>
+          <provides>
+            <version>1.6</version>
+            <vendor>Sun</vendor>
+            <id>sun_1.6</id>
+            <custom>foo</custom>
+          </provides>
+          <configuration>
+            <jdkHome>/opt/jdk/sun/1.6</jdkHome>
+            <fooHome>/usr/local/bin/bash</fooHome>
+          </configuration>
+        </toolchain>
+      </toolchains>`;
+    const result = `<?xml version="1.0"?>
+<toolchains xmlns="http://maven.apache.org/TOOLCHAINS/1.1.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd">
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>17</version>
+      <vendor>Eclipse Temurin</vendor>
+      <id>temurin_17</id>
+    </provides>
+    <configuration>
+      <jdkHome>/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64</jdkHome>
+    </configuration>
+  </toolchain>
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>1.6</version>
+      <vendor>Sun</vendor>
+      <id>sun_1.6</id>
+      <custom>foo</custom>
+    </provides>
+    <configuration>
+      <jdkHome>/opt/jdk/sun/1.6</jdkHome>
+      <fooHome>/usr/local/bin/bash</fooHome>
+    </configuration>
+  </toolchain>
+</toolchains>`;
+
+    fs.mkdirSync(m2Dir, {recursive: true});
+    fs.writeFileSync(toolchainsFile, originalFile);
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+
+    await toolchains.createToolchainsSettings({
+      jdkInfo,
+      settingsDirectory: m2Dir,
+      overwriteSettings: true
+    });
+
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+    expect(fs.readFileSync(toolchainsFile, 'utf-8')).toEqual(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    );
+    expect(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    ).toEqual(result);
+  }, 100000);
+
+  it('does not discard existing, custom toolchain definitions', async () => {
+    const jdkInfo = {
+      version: '17',
+      vendor: 'Eclipse Temurin',
+      id: 'temurin_17',
+      jdkHome: '/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64'
+    };
+
+    const originalFile = `<toolchains>
+        <toolchain>
+            <type>foo</type>
+            <provides>
+                <custom>baz</custom>
+            </provides>
+            <configuration>
+                <fooHome>/usr/local/bin/foo</fooHome>
+            </configuration>
+        </toolchain>
+      </toolchains>`;
+    const result = `<?xml version="1.0"?>
+<toolchains xmlns="http://maven.apache.org/TOOLCHAINS/1.1.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd">
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>17</version>
+      <vendor>Eclipse Temurin</vendor>
+      <id>temurin_17</id>
+    </provides>
+    <configuration>
+      <jdkHome>/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64</jdkHome>
+    </configuration>
+  </toolchain>
+  <toolchain>
+    <type>foo</type>
+    <provides>
+      <custom>baz</custom>
+    </provides>
+    <configuration>
+      <fooHome>/usr/local/bin/foo</fooHome>
+    </configuration>
+  </toolchain>
+</toolchains>`;
+
+    fs.mkdirSync(m2Dir, {recursive: true});
+    fs.writeFileSync(toolchainsFile, originalFile);
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+
+    await toolchains.createToolchainsSettings({
+      jdkInfo,
+      settingsDirectory: m2Dir,
+      overwriteSettings: true
+    });
+
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+    expect(fs.readFileSync(toolchainsFile, 'utf-8')).toEqual(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    );
+    expect(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    ).toEqual(result);
+  }, 100000);
+
+  it('does not duplicate existing toolchain definitions', async () => {
+    const jdkInfo = {
+      version: '17',
+      vendor: 'Eclipse Temurin',
+      id: 'temurin_17',
+      jdkHome: '/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64'
+    };
+
+    const originalFile = `<toolchains>
+      <toolchain>
+        <type>jdk</type>
+        <provides>
+          <version>17</version>
+          <vendor>Eclipse Temurin</vendor>
+          <id>temurin_17</id>
+        </provides>
+        <configuration>
+          <jdkHome>/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64</jdkHome>
+        </configuration>
+      </toolchain>
+      </toolchains>`;
+    const result = `<?xml version="1.0"?>
+<toolchains xmlns="http://maven.apache.org/TOOLCHAINS/1.1.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd">
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>17</version>
+      <vendor>Eclipse Temurin</vendor>
+      <id>temurin_17</id>
+    </provides>
+    <configuration>
+      <jdkHome>/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64</jdkHome>
+    </configuration>
+  </toolchain>
+</toolchains>`;
+
+    fs.mkdirSync(m2Dir, {recursive: true});
+    fs.writeFileSync(toolchainsFile, originalFile);
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+
+    await toolchains.createToolchainsSettings({
+      jdkInfo,
+      settingsDirectory: m2Dir,
+      overwriteSettings: true
+    });
+
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+    expect(fs.readFileSync(toolchainsFile, 'utf-8')).toEqual(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    );
+    expect(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    ).toEqual(result);
+  }, 100000);
+
+  it('does not duplicate existing toolchain definitions if multiple exist', async () => {
+    const jdkInfo = {
+      version: '17',
+      vendor: 'Eclipse Temurin',
+      id: 'temurin_17',
+      jdkHome: '/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64'
+    };
+
+    const originalFile = `<toolchains>
+        <toolchain>
+          <type>jdk</type>
+          <provides>
+            <version>1.6</version>
+            <vendor>Sun</vendor>
+            <id>sun_1.6</id>
+          </provides>
+          <configuration>
+            <jdkHome>/opt/jdk/sun/1.6</jdkHome>
+          </configuration>
+        </toolchain>
+      <toolchain>
+        <type>jdk</type>
+        <provides>
+          <version>17</version>
+          <vendor>Eclipse Temurin</vendor>
+          <id>temurin_17</id>
+        </provides>
+        <configuration>
+          <jdkHome>/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64</jdkHome>
+        </configuration>
+      </toolchain>
+      </toolchains>`;
+    const result = `<?xml version="1.0"?>
+<toolchains xmlns="http://maven.apache.org/TOOLCHAINS/1.1.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd">
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>17</version>
+      <vendor>Eclipse Temurin</vendor>
+      <id>temurin_17</id>
+    </provides>
+    <configuration>
+      <jdkHome>/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64</jdkHome>
+    </configuration>
+  </toolchain>
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>1.6</version>
+      <vendor>Sun</vendor>
+      <id>sun_1.6</id>
+    </provides>
+    <configuration>
+      <jdkHome>/opt/jdk/sun/1.6</jdkHome>
+    </configuration>
+  </toolchain>
+</toolchains>`;
+
+    fs.mkdirSync(m2Dir, {recursive: true});
+    fs.writeFileSync(toolchainsFile, originalFile);
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+
+    await toolchains.createToolchainsSettings({
+      jdkInfo,
+      settingsDirectory: m2Dir,
+      overwriteSettings: true
+    });
+
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+    expect(fs.readFileSync(toolchainsFile, 'utf-8')).toEqual(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    );
+    expect(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    ).toEqual(result);
+  }, 100000);
+
+  it('handles an empty list of existing toolchains correctly', async () => {
+    const jdkInfo = {
+      version: '17',
+      vendor: 'Eclipse Temurin',
+      id: 'temurin_17',
+      jdkHome: '/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64'
+    };
+
+    const originalFile = `<toolchains>
+      </toolchains>`;
+    const result = `<?xml version="1.0"?>
+<toolchains xmlns="http://maven.apache.org/TOOLCHAINS/1.1.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd">
+  <toolchain>
+    <type>jdk</type>
+    <provides>
+      <version>17</version>
+      <vendor>Eclipse Temurin</vendor>
+      <id>temurin_17</id>
+    </provides>
+    <configuration>
+      <jdkHome>/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64</jdkHome>
+    </configuration>
+  </toolchain>
+</toolchains>`;
+
+    fs.mkdirSync(m2Dir, {recursive: true});
+    fs.writeFileSync(toolchainsFile, originalFile);
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+
+    await toolchains.createToolchainsSettings({
+      jdkInfo,
+      settingsDirectory: m2Dir,
+      overwriteSettings: true
+    });
+
+    expect(fs.existsSync(m2Dir)).toBe(true);
+    expect(fs.existsSync(toolchainsFile)).toBe(true);
+    expect(fs.readFileSync(toolchainsFile, 'utf-8')).toEqual(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    );
+    expect(
+      toolchains.generateToolchainDefinition(
+        originalFile,
+        jdkInfo.version,
+        jdkInfo.vendor,
+        jdkInfo.id,
+        jdkInfo.jdkHome
+      )
+    ).toEqual(result);
+  }, 100000);
+
+  it('handles an empty existing toolchains.xml correctly', async () => {
+    const jdkInfo = {
+      version: '17',
+      vendor: 'Eclipse Temurin',
+      id: 'temurin_17',
+      jdkHome: '/opt/hostedtoolcache/Java_Temurin-Hotspot_jdk/17.0.1-12/x64'
+    };
+
+    const originalFile = ``;
+    const result = `<?xml version="1.0"?>
+<toolchains xmlns="http://maven.apache.org/TOOLCHAINS/1.1.0"
+  xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
+  xsi:schemaLocation="http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd">
  <toolchain>
    <type>jdk</type>
    <provides>
--- a/dist/setup/index.js
+++ b/dist/setup/index.js
@ -126108,31 +126108,7 @@ function createToolchainsSettings({ jdkInfo, settingsDirectory, overwriteSetting
 exports.createToolchainsSettings = createToolchainsSettings;
 // only exported for testing purposes
 function generateToolchainDefinition(original, version, vendor, id, jdkHome) {
-    let xmlObj;
-    if (original === null || original === void 0 ? void 0 : original.length) {
-        xmlObj = (0, xmlbuilder2_1.create)(original)
-            .root()
-            .ele({
-            toolchain: {
-                type: 'jdk',
-                provides: {
-                    version: `${version}`,
-                    vendor: `${vendor}`,
-                    id: `${id}`
-                },
-                configuration: {
-                    jdkHome: `${jdkHome}`
-                }
-            }
-        });
-    }
-    else
-        xmlObj = (0, xmlbuilder2_1.create)({
-            toolchains: {
-                '@xmlns': 'http://maven.apache.org/TOOLCHAINS/1.1.0',
-                '@xmlns:xsi': 'http://www.w3.org/2001/XMLSchema-instance',
-                '@xsi:schemaLocation': 'http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd',
-                toolchain: [
+    let jsToolchains = [
        {
            type: 'jdk',
            provides: {
@ -126144,10 +126120,41 @@ function generateToolchainDefinition(original, version, vendor, id, jdkHome) {
                jdkHome: `${jdkHome}`
            }
        }
-                ]
+    ];
+    if (original === null || original === void 0 ? void 0 : original.length) {
+        // convert existing toolchains into TS native objects for better handling
+        // xmlbuilder2 will convert the document into a `{toolchains: { toolchain: [] | {} }}` structure
+        // instead of the desired `toolchains: [{}]` one or simply `[{}]`
+        const jsObj = (0, xmlbuilder2_1.create)(original)
+            .root()
+            .toObject();
+        if (jsObj.toolchains && jsObj.toolchains.toolchain) {
+            // in case only a single child exists xmlbuilder2 will not create an array and using verbose = true equally doesn't work here
+            // See https://oozcitak.github.io/xmlbuilder2/serialization.html#js-object-and-map-serializers for details
+            if (Array.isArray(jsObj.toolchains.toolchain)) {
+                jsToolchains.push(...jsObj.toolchains.toolchain);
            }
-        });
-    return xmlObj.end({
+            else {
+                jsToolchains.push(jsObj.toolchains.toolchain);
+            }
+        }
+        // remove potential duplicates based on type & id (which should be a unique combination);
+        // self.findIndex will only return the first occurrence, ensuring duplicates are skipped
+        jsToolchains = jsToolchains.filter((value, index, self) => 
+        // ensure non-jdk toolchains are kept in the results, we must not touch them because they belong to the user
+        value.type !== 'jdk' ||
+            index ===
+                self.findIndex(t => t.type === value.type && t.provides.id === value.provides.id));
+    }
+    // TODO: technically bad because we shouldn't re-create the toolchains root node (with possibly different schema values) if it already exists, however, just overriding the toolchain array with xmlbuilder2 is … uh non-trivial
+    return (0, xmlbuilder2_1.create)({
+        toolchains: {
+            '@xmlns': 'http://maven.apache.org/TOOLCHAINS/1.1.0',
+            '@xmlns:xsi': 'http://www.w3.org/2001/XMLSchema-instance',
+            '@xsi:schemaLocation': 'http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd',
+            toolchain: jsToolchains
+        }
+    }).end({
        format: 'xml',
        wellFormed: false,
        headless: false,
--- a/src/toolchains.ts
+++ b/src/toolchains.ts
@ -84,31 +84,7 @@ export function generateToolchainDefinition(
  id: string,
  jdkHome: string
 ) {
-  let xmlObj;
-  if (original?.length) {
-    xmlObj = xmlCreate(original)
-      .root()
-      .ele({
-        toolchain: {
-          type: 'jdk',
-          provides: {
-            version: `${version}`,
-            vendor: `${vendor}`,
-            id: `${id}`
-          },
-          configuration: {
-            jdkHome: `${jdkHome}`
-          }
-        }
-      });
-  } else
-    xmlObj = xmlCreate({
-      toolchains: {
-        '@xmlns': 'http://maven.apache.org/TOOLCHAINS/1.1.0',
-        '@xmlns:xsi': 'http://www.w3.org/2001/XMLSchema-instance',
-        '@xsi:schemaLocation':
-          'http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd',
-        toolchain: [
+  let jsToolchains: Toolchain[] = [
    {
      type: 'jdk',
      provides: {
@ -120,11 +96,47 @@ export function generateToolchainDefinition(
        jdkHome: `${jdkHome}`
      }
    }
-        ]
+  ];
+  if (original?.length) {
+    // convert existing toolchains into TS native objects for better handling
+    // xmlbuilder2 will convert the document into a `{toolchains: { toolchain: [] | {} }}` structure
+    // instead of the desired `toolchains: [{}]` one or simply `[{}]`
+    const jsObj = xmlCreate(original)
+      .root()
+      .toObject() as unknown as ExtractedToolchains;
+    if (jsObj.toolchains && jsObj.toolchains.toolchain) {
+      // in case only a single child exists xmlbuilder2 will not create an array and using verbose = true equally doesn't work here
+      // See https://oozcitak.github.io/xmlbuilder2/serialization.html#js-object-and-map-serializers for details
+      if (Array.isArray(jsObj.toolchains.toolchain)) {
+        jsToolchains.push(...jsObj.toolchains.toolchain);
+      } else {
+        jsToolchains.push(jsObj.toolchains.toolchain);
+      }
    }
-    });

-  return xmlObj.end({
+    // remove potential duplicates based on type & id (which should be a unique combination);
+    // self.findIndex will only return the first occurrence, ensuring duplicates are skipped
+    jsToolchains = jsToolchains.filter(
+      (value, index, self) =>
+        // ensure non-jdk toolchains are kept in the results, we must not touch them because they belong to the user
+        value.type !== 'jdk' ||
+        index ===
+          self.findIndex(
+            t => t.type === value.type && t.provides.id === value.provides.id
+          )
+    );
+  }
+
+  // TODO: technically bad because we shouldn't re-create the toolchains root node (with possibly different schema values) if it already exists, however, just overriding the toolchain array with xmlbuilder2 is … uh non-trivial
+  return xmlCreate({
+    toolchains: {
+      '@xmlns': 'http://maven.apache.org/TOOLCHAINS/1.1.0',
+      '@xmlns:xsi': 'http://www.w3.org/2001/XMLSchema-instance',
+      '@xsi:schemaLocation':
+        'http://maven.apache.org/TOOLCHAINS/1.1.0 https://maven.apache.org/xsd/toolchains-1.1.0.xsd',
+      toolchain: jsToolchains
+    }
+  }).end({
    format: 'xml',
    wellFormed: false,
    headless: false,
@ -167,3 +179,22 @@ async function writeToolchainsFileToDisk(
    flag: 'w'
  });
 }
+
+interface ExtractedToolchains {
+  toolchains: {
+    toolchain: Toolchain[] | Toolchain;
+  };
+}
+
+// Toolchain type definition according to Maven Toolchains XSD 1.1.0
+interface Toolchain {
+  type: string;
+  provides:
+    | {
+        version: string;
+        vendor: string;
+        id: string;
+      }
+    | any;
+  configuration: any;
+}