fix: autocomplete table names after FROM/JOIN keywords

packages/server/src/complete/complete.ts

@@ -111,7 +111,7 @@ class Completer {
           // Incomplete sub query 'SELECT sub FROM (SELECT e. FROM employees e) sub'
           this.addCandidatesForIncompleteSubquery(fromNodeOnCursor)
         } else {
-          this.addCandidatesForSelectQuery(e, fromNodes)
+          this.addCandidatesForSelectQuery(e, fromNodes, parsedFromClause)
           const expectedLiteralNodes =
             e.expected?.filter(
               (v): v is ExpectedLiteralNode => v.type === 'literal'
@@ -239,7 +239,11 @@ class Completer {
     this.addCandidatesForTables(this.schema.tables, false)
   }
 
-  addCandidatesForSelectQuery(e: ParseError, fromNodes: FromTableNode[]) {
+  addCandidatesForSelectQuery(
+    e: ParseError,
+    fromNodes: FromTableNode[],
+    parsedFromClause: FromClauseParserResult
+  ) {
     const subqueryTables = createTablesFromFromNodes(fromNodes)
     const schemaAndSubqueries = this.schema.tables.concat(subqueryTables)
     this.addCandidatesForSelectStar(fromNodes, schemaAndSubqueries)
@@ -263,8 +267,19 @@ class Completer {
       isPosInLocation(tableNode.location, this.pos)
     )
     const isCursorInsideFromClause = fromNodesContainingCursor.length > 0
-    if (isCursorInsideFromClause) {
-      // only add table candidates if the cursor is inside a FROM clause or JOIN clause, etc.
+
+    // Check if cursor is right after FROM keyword (no table typed yet)
+    const afterFromClause = parsedFromClause.after?.trim().toUpperCase() || ''
+    const isCursorAfterFromKeyword =
+      afterFromClause === 'FROM' ||
+      afterFromClause.startsWith('FROM ') ||
+      /^(INNER |LEFT |RIGHT |FULL |FULL OUTER |CROSS |NATURAL |OUTER )?JOIN( |$)/.test(
+        afterFromClause
+      )
+
+    if (isCursorInsideFromClause || isCursorAfterFromKeyword) {
+      // add table candidates if the cursor is inside a FROM clause, JOIN clause,
+      // or right after FROM/JOIN keyword waiting for a table name
       this.addCandidatesForTables(schemaAndSubqueries, true)
     }
 

packages/server/test/complete.test.ts

@@ -241,6 +241,24 @@ describe('From clause', () => {
     expect(result.candidates[0].insertText).toEqual('TABLE1')
   })
 
+  test('from clause: complete TableName after FROM keyword with space', () => {
+    const result = complete(
+      'SELECT * FROM ',
+      { line: 0, column: 14 },
+      SIMPLE_SCHEMA
+    )
+    expect(result.candidates.map((v) => v.label)).toContain('TABLE1')
+  })
+
+  test('from clause: complete TableName after FROM keyword with space:multi line', () => {
+    const result = complete(
+      'SELECT *\nFROM ',
+      { line: 1, column: 5 },
+      SIMPLE_SCHEMA
+    )
+    expect(result.candidates.map((v) => v.label)).toContain('TABLE1')
+  })
+
   test('from clause: complete TableName:multi lines', () => {
     const result = complete(
       'SELECT TABLE1.COLUMN1\nFROM T',
@@ -277,6 +295,69 @@ describe('From clause', () => {
     )
     expect(result.candidates.map((v) => v.label)).toContain('ON')
   })
+
+  test('from clause: complete TableName after JOIN keyword with space', () => {
+    const result = complete(
+      'SELECT * FROM TABLE1 JOIN ',
+      { line: 0, column: 26 },
+      SIMPLE_SCHEMA
+    )
+    expect(result.candidates.map((v) => v.label)).toContain('TABLE1')
+  })
+
+  test('from clause: complete TableName after INNER JOIN keyword with space', () => {
+    const result = complete(
+      'SELECT * FROM TABLE1 INNER JOIN ',
+      { line: 0, column: 32 },
+      SIMPLE_SCHEMA
+    )
+    expect(result.candidates.map((v) => v.label)).toContain('TABLE1')
+  })
+
+  test('from clause: complete TableName after LEFT JOIN keyword with space', () => {
+    const result = complete(
+      'SELECT * FROM TABLE1 LEFT JOIN ',
+      { line: 0, column: 31 },
+      SIMPLE_SCHEMA
+    )
+    expect(result.candidates.map((v) => v.label)).toContain('TABLE1')
+  })
+
+  test('from clause: complete TableName after RIGHT JOIN keyword with space', () => {
+    const result = complete(
+      'SELECT * FROM TABLE1 RIGHT JOIN ',
+      { line: 0, column: 32 },
+      SIMPLE_SCHEMA
+    )
+    expect(result.candidates.map((v) => v.label)).toContain('TABLE1')
+  })
+
+  test('from clause: complete TableName after CROSS JOIN keyword with space', () => {
+    const result = complete(
+      'SELECT * FROM TABLE1 CROSS JOIN ',
+      { line: 0, column: 32 },
+      SIMPLE_SCHEMA
+    )
+    expect(result.candidates.map((v) => v.label)).toContain('TABLE1')
+  })
+
+  test('from clause: complete TableName after FULL OUTER JOIN keyword with space', () => {
+    const result = complete(
+      'SELECT * FROM TABLE1 FULL OUTER JOIN ',
+      { line: 0, column: 37 },
+      SIMPLE_SCHEMA
+    )
+    expect(result.candidates.map((v) => v.label)).toContain('TABLE1')
+  })
+
+  test('from clause: complete TableName after NATURAL JOIN keyword with space', () => {
+    const result = complete(
+      'SELECT * FROM TABLE1 NATURAL JOIN ',
+      { line: 0, column: 34 },
+      SIMPLE_SCHEMA
+    )
+    expect(result.candidates.map((v) => v.label)).toContain('TABLE1')
+  })
 })
 
 describe('Where clause', () => {